Heart valve docking coils and systems

ABSTRACT

Anchoring or docking devices configured to be positioned at a native valve of a human heart and to provide structural support for docking a prosthetic valve therein. The docking devices can have coiled structures that define an inner space in which the prosthetic valve can be held. The docking devices can have enlarged end regions with circular or non-circular shapes, for example, to facilitate implantation of the docking device or to better hold the docking device in position once deployed. The docking devices can be laser-cut tubes with locking wires to assist in better maintaining a shape of the docking device. The docking devices can include various features to promote friction, such as frictional cover layers. Such docking devices can have ends configured to more securely attach the cover layers to cores of the docking devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/682,287, filed Aug. 21, 2017, which claims priority to U.S.Provisional Patent Application Ser. No. 62/395,940, filed on Sep. 16,2016 and U.S. Provisional Patent Application Ser. No. 62/380,117, filedon Aug. 26, 2016. These applications, as well as U.S. patent applicationSer. No. 14/372,953, entitled “Mitral Valve Docking Devices, Systems,and Methods,” filed on Jul. 17, 2014, are all incorporated herein byreference in their entireties.

FIELD OF THE INVENTION

The invention generally relates to medical devices and procedurespertaining to prosthetic heart valves. More specifically, the inventionrelates to replacement of heart valves that may have malformationsand/or dysfunctions. Embodiments of the invention relate to an anchor ordocking device that can hold and maintain a positioning of a prostheticheart valve for replacing the function of a native heart valve, forexample, for a mitral or tricuspid valve replacement procedure, as wellas deployment procedures associated with the implantation of such ananchor or docking device and/or of an assembly including the anchor ordocking device and a prosthetic heart valve.

BACKGROUND Description of Related Art

Referring first to FIGS. 1 and 2, the mitral valve 50 controls the flowof blood between the left atrium 52 and the left ventricle 54 of thehuman heart. After the left atrium 52 receives oxygenated blood from thelungs via the pulmonary veins, the mitral valve 50 permits the flow ofthe oxygenated blood from the left atrium 52 into the left ventricle 54.When the left ventricle 54 contracts, the oxygenated blood that was heldin the left ventricle 54 is delivered through the aortic valve 56 andthe aorta 58 to the rest of the body. Meanwhile, the mitral valve shouldclose during ventricular contraction to prevent any blood from flowingback into the left atrium.

When the left ventricle contracts, the blood pressure in the leftventricle increases substantially, which serves to urge the mitral valveclosed. Due to the large pressure differential between the leftventricle and the left atrium during this time, a large amount ofpressure is placed on the mitral valve, leading to a possibility ofprolapse, or eversion of the leaflets of the mitral valve back into theatrium. A series of chordae tendineae 62 therefore connect the leafletsof the mitral valve to papillary muscles located on the walls of theleft ventricle, where both the chordae tendineae and the papillarymuscles are tensioned during ventricular contraction to hold theleaflets in the closed position and to prevent them from extending backtowards the left atrium. This helps prevent backflow of oxygenated bloodback into the left atrium. The chordae tendineae 62 are schematicallyillustrated in both the heart cross-section of FIG. 1 and the top viewof the mitral valve of FIG. 2.

A general shape of the mitral valve and its leaflets as viewed from theleft atrium is shown in FIG. 2. Commissures 64 are located at the endsof the mitral valve 50 where the anterior leaflet 66 and the posteriorleaflet 68 come together. Various complications of the mitral valve canpotentially cause fatal heart failure. One form of valvular heartdisease is mitral valve leak or mitral regurgitation, characterized byabnormal leaking of blood from the left ventricle through the mitralvalve back into the left atrium. This can be caused, for example, bydilation of the left ventricle causing the native mitral leaflets to notcoapt completely, resulting in a leak, by damage to the native leaflets,or weakening of (or damage to) the chordae tendineae and/or papillarymuscles. In these circumstances, it may be desirable to repair themitral valve or to replace the functionality of the mitral valve withthat of a prosthetic heart valve.

With respect to valve replacement, while open surgical procedure optionsare more readily available, there has been much less development interms of commercially available ways to replace a mitral valve throughcatheter implantation and/or other minimal or less invasive procedures.In contrast, the field of transcatheter aortic valve replacement hasdeveloped much more and has gained widespread success. This discrepancystems, in part, from replacement of a mitral valve being more difficultthan aortic valve replacement in many respects, for example, due to thenon-circular physical structure of the mitral valve, its sub-annularanatomy, and more difficult access to the valve. Due to the successes inthe development of transcatheter aortic valve technology, it could bebeneficial to use the same or similar circular valve prostheses formitral valve replacements.

One of the most prominent obstacles for mitral valve replacement iseffective anchoring or retention of the valve at the mitral position,due to the valve being subject to a large cyclic load. As noted above,another issue with mitral valve replacement is the size and shape of thenative mitral annulus, as can be seen in FIG. 2. Aortic valves are morecircular or cylindrical in shape than mitral valves. Also, the mitraland tricuspid valves are both larger than the aortic valve, and moreelongate in shape, making them more difficult and unconventional sitesfor implanting a replacement valve with a generally circular orcylindrical valve frame. A circular prosthetic valve that is too smallcan result in leaking around the implant (i.e., paravalvular leakage) ifa good seal is not established around the valve, while a circularprosthetic valve that is too large can stretch out and damage thenarrower parts of the native mitral annulus. Further, in many cases, theneed for aortic valve replacement arises due, for example, to aorticvalve stenosis, where the aortic valve narrows due to calcification orother hardening of the native leaflets. Therefore, the aortic annulusgenerally forms a more compact, rigid, and stable anchoring site for aprosthetic valve than the mitral annulus, which is both larger than theaortic annulus and non-circular. Instances of mitral valve regurgitationare unlikely to provide such a good anchoring site. Also, the presenceof the chordae tendineae and other anatomy at the mitral position canform obstructions that make it much more challenging to adequatelyanchor a device at the mitral position.

Other obstacles to effective mitral valve replacement can stem from thelarge cyclic loads the mitral valve undergoes and the need to establisha sufficiently strong and stable anchoring and retention. Also, even aslight shift in the alignment of the valve can still lead to blood flowthrough the valve or other parts of the heart being obstructed orotherwise negatively impacted.

SUMMARY

One way to apply existing circular or cylindrical transcatheter valvetechnology to non-circular valve replacement (e.g., mitral valvereplacement, tricuspid valve replacement, etc.) would be to use ananchor (e.g., a mitral anchor) or docking station that forms orotherwise provides a more circular docking site at the native valveposition (e.g., mitral valve position) to hold such prosthetic valves.In this manner, existing expandable transcatheter valves developed forthe aortic position, or similar valves that have been slightly modifiedto more effectively replicate mitral valve function, could be moresecurely implanted in such docking stations positioned at the nativevalve annulus (e.g., native mitral annulus). The docking station canfirst be positioned at the native valve annulus, and thereafter, thevalve implant or transcatheter heart valve can be advanced andpositioned through the docking station while in a collapsed position,and can then be expanded, for example, via self-expansion (e.g., in thecase of valves that are constructed with NiTi or another shape memorymaterial), balloon expansion, or mechanical expansion, so that the frameof the prosthetic valve pushes radially against the docking stationand/or tissue between the two to hold the valve in place. Preferably,the docking station can also be delivered minimally or less invasively,for example, via the same or similar transcatheter approaches as usedfor delivery of a transcatheter heart valve, so that a completelyseparate procedure is not needed to implant the docking station prior todelivery of the prosthetic valve.

It would therefore be desirable to provide devices and methods that canbe utilized to facilitate the docking or anchoring of such valves.Embodiments of the invention provide a stable docking station or dockingdevice for retaining a prosthetic valve (e.g., a prosthetic mitralvalve). Other features are provided to improve the deployment,positioning, stability, and/or integration of such docking stationsand/or replacement prostheses intended to be held therein. These devicesand methods will more securely hold prosthetic valves, and can alsoprevent or greatly reduce regurgitation or leaking of blood around theprosthetic valves. Such docking devices and methods can be used forvarious valve replacement procedures, for example, for mitral,tricuspid, pulmonary, or aortic valve replacements, to provide moresecure and robust anchoring and holding of valve implants at the nativeannuluses at those positions.

Docking devices for docking a prosthetic valve at a native valve (e.g.,mitral valve, tricuspid valve, etc.) of a heart can include variousfeatures, components, and characteristics. For example, such dockingdevices can include a coiled anchor that has at least one central turn(e.g., a full rotation or partial-rotation central turn) defining acentral turn diameter. The at least one central turn can be one or morefunctional turns/coils. The coiled anchor can also include a lower turnextending from the at least one central turn defining a diameter that isgreater than the central turn diameter. The lower turn can be a leadingturn/coil. The coiled anchor can also include an upper turn connected tothe central turn. The upper turn can be one or more stabilizingturns/coils. The upper turn can be shaped to have a first diameter alonga first axis and a second diameter along a second axis. The first axisdiameter of the upper turn can be greater than the central turndiameter, and the second axis diameter can be greater than the centralturn diameter and less than the lower turn diameter. The various coiledanchors described herein can be configured to be implanted at the nativevalve (e.g., native mitral valve, tricuspid valve, etc.) with at least aportion of the at least one central turn of the coiled anchor positionedin a chamber (e.g., a left ventricle) of the heart and around valveleaflets of the native valve.

Any of the coiled anchors described herein can also include an extensionhaving a length extending from an upper end of the at least one centralturn to an upper turn/coil or stabilization turn/coil. The extension canhave a smaller or reduced thickness compared to other parts of thecoiled anchor, e.g., the at least one central turn, upper turn, lowerturn, etc. The extension can extend vertically at an angle between60-120 degrees, 70-110 degrees, 80-100 degrees, 90 degrees relative tothe at least one central turn.

The various docking devices for docking a prosthetic valve at a nativevalve of a heart can have a coiled anchor (e.g., which can be the sameas or similar to other coiled anchors described in this disclosure) thathas a proximal tip and a distal tip. The coiled anchor can include atleast one central turn (e.g., a full or partial central turn, which canbe the same as or similar to other central or functional turns describedin this disclosure). The at least one central turn can have a firstthickness and define a central turn diameter. Any of the coiled anchorsdescribed herein can also include an extension having a length extendingfrom an upper end of the at least one central turn. The coiled anchorcan also include an upper turn (e.g., with can be the same as or similarto other upper turns or stabilizing turns/coils described in thisdisclosure) extending from an upper end of the extension. The extensioncan have a second thickness that is less than the first thickness. Theupper turn can have a third thickness that is greater than the secondthickness. As discussed above, the coiled anchor can configured to beimplanted at the native valve (e.g., native mitral valve, tricuspidvalve, etc.) with at least a portion of the at least one full or partialcentral turn of the coiled anchor positioned in a chamber (e.g., leftventricle) of the heart and around valve leaflets (e.g., mitral valveleaflets) of the native heart valve.

The various docking devices for docking a prosthetic valve at a nativevalve of a heart can also have a coiled anchor (e.g., which can be thesame as or similar to other coiled anchors described in this disclosure)that has a proximal tip and a distal tip and at least one central turn(e.g., a full or partial central turn, which can be the same as orsimilar to other central turns/coils or functional turns/coils describedin this disclosure) that defines a diameter. The coiled anchor can alsohave an upper turn that is connected to the at least one central turn. Acover layer can surround the coiled anchor along all or at least a partof the at least one central turn. The cover layer can be connected tothe coiled anchor. At least one friction enhancing layer can be disposedover the coiled anchor and/or the cover layer. The at least one frictionenhancing layer can be disposed over at least a portion of the at leastone central turn. The coiled anchor can be configured such that noportion of the upper turn is covered by the friction enhancing layer.The coiled anchor can also be configured to be implantable at a nativevalve (e.g., a native mitral valve, etc.) with at least a portion of theat least one central turn of the coiled anchor positioned in a chamber(e.g., left ventricle) of the heart and around valve leaflets of thenative valve.

Any of the coiled anchors of any of the docking devices described hereincan include one or more cover layers that surround all or at least partof the coiled anchor or a core of the coiled anchor. For example, acover layer can surround all or at least part of the at least onecentral turn (or all of the central turn(s)/coil(s) or functionalturn(s)/coil(s) of the coiled anchor) and/or other parts of the coiledanchor. The cover layer can be connected to the coiled anchor in variousways. The cover layer can be a high friction cover layer, a low frictioncover layer, or both a low friction cover layer and a high frictioncover layer used together. The low friction cover layer can beconfigured to surround a core of the coiled anchor (e.g., the fulllength of the coiled anchor) and extend past the proximal tip and/ordistal tip. The low friction cover layer can form a tapered or roundedtip at its distal end and/or at its proximal end. A high friction coverlayer or higher friction cover layer (e.g., higher than the low frictioncover layer) can surround a portion of the low friction cover layerand/or a portion of the coiled anchor (e.g., all or a part of the atleast one central turn).

Any of the coiled anchors described herein can include at least onefriction enhancing element or multiple friction enhancing elements. Theat least one friction enhancing element or friction enhancing elementscan be positioned over all or a portion of the coiled anchor or acovering/layer on the coiled anchor. The at least one friction enhancingelement can be or include a plurality of bulges on the surface of thecoiled anchor or on the surface of the covering. The bulges can be madeof PET, polymer, fabric, or another material. The bulges can extendalong a length of the coiled anchor or the covering along at least apart of the central turn(s)/coil(s). Optionally, the at least onefriction enhancing element can be or include a plurality of lock and keycutouts in an outer surface of the coiled anchor. The lock cutouts canbe grooves formed in the outer surface of the coiled anchor, and the keycutouts can be protrusions extending outward from the coiled anchor,which can be sized and shaped to fit into the lock cutouts.

Systems for implanting a docking device at a native valve of a heart caninclude a docking device (e.g., any docking device described above orelsewhere in this disclosure). The docking device can include an openingor bore, and the system can include a suture threaded through theopening or bore. The system can also include a delivery catheter, and apusher device disposed in the delivery catheter. The pusher device caninclude a central lumen that accepts the suture or through which thesuture passes. The pusher device and suture can be arranged such thatpulling the suture pulls the coiled anchor against the pusher device,and retracting the pusher device into the delivery catheter retracts thecoiled anchor into the delivery catheter. The suture can be disposed inthe central lumen such that pulling the suture and/or the pusher deviceproximally relative to the delivery catheter retracts the coiled anchoror delivery device into the delivery catheter.

A docking device for docking a prosthetic valve at a native valve of aheart can have a coiled anchor that includes a hollow tube. The hollowtube can have a proximal lock feature and a distal lock feature. Therecan be a plurality of cuts through a portion of the tube. The cuts canhave a pattern and shape that incorporates one or both of longitudinaland transverse cuts. Where the cuts have a pattern and shape thatincorporate both longitudinal and transverse cuts, these can form teethand grooves in the hollow tube. The docking device can also have a wire,and the distal end of the wire can be secured to the distal lockfeature. A length of the wire (e.g., the full length or a portionthereof) can extend through the hollow tube and apply a radially inwardtension on the hollow tube. The hollow tube is configured to at leastpartially encircle leaflets of a native mitral valve and provide adocking surface for an expandable prosthetic valve.

Methods used to implant a docking device for a prosthetic valve at anative heart valve can include a variety of steps (e.g., any of thesteps described throughout this disclosure). The docking deviceimplanted with these methods can be any of the docking devices describedherein. For example, a docking device implantable with these steps canhave a coiled anchor having at least one full or partial turn defining acentral diameter, an extension having a length extending from an upperend of the at least one central turn, and an upper turn extending froman upper end of the extension. As distal end of a delivery catheter canbe positioned into a first chamber (e.g., a left atrium) of a heart.Optionally, the delivery catheter can be advanced and positioned througha guide sheath previously implanted. The delivery catheter can containthe docking device in a first configuration. A distal end of a dockingdevice can be advanced from the delivery catheter so that the dockingdevice adopts a second configuration as it is advanced and/or when it isimplanted. The docking device is advanced through a valve annulus (e.g.,a native mitral valve annulus) and into a second chamber of the heart(e.g., the left ventricle) such that a distal tip loosely encircles anychordae and native leaflets of the native valve (e.g., of a mitralvalve). The extension of the docking device can be advanced such thatits upper end is positioned in the first chamber (e.g., the leftatrium). The upper portion of the docking device can be advanced intothe first chamber (e.g., the left atrium) and released, such that theupper portion is in contact with the first chamber wall (e.g., the leftatrium wall). A replacement prosthetic valve can be implanted in thedocking device. For example, a replacement valve can be inserted in aninner space defined by the docking device in the second configuration.The replacement valve can be radially expanded until there is aretention force between the replacement valve and the docking device tohold the replacement valve in a stable position. Native leaflets orother tissue can be clamped between the delivery device and theprosthetic valve.

Valve replacement can be realized through the use of a coiled anchor ordocking device at the native valve site for docking an expandabletranscatheter heart valve therein. The coiled anchors or docking devicesprovide a more stable base or site against which the prosthetic valvescan be expanded. Embodiments of the invention thus provide a more robustway to implant a replacement heart valve, even at sites such as a nativemitral annulus, where the annulus itself may be non-circular orotherwise variably shaped.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will become apparentfrom the description of embodiments using the accompanying drawings. Inthe drawings:

FIG. 1 shows a schematic cross-sectional view of a human heart;

FIG. 2 shows a schematic top view of a mitral valve annulus of a heart;

FIG. 3 shows a perspective view of a coil anchor according to a firstembodiment of the invention;

FIG. 4 shows a side view of the coil anchor of FIG. 3;

FIG. 5 shows a top view of the coil anchor of FIGS. 3 and 4;

FIG. 6 shows a cross-sectional view of a portion of a heart during astep of delivering the coil anchor of FIGS. 3 to 5 to the native mitralannulus;

FIG. 7 shows a cross-sectional view of a portion of a heart during afurther step of delivering the coil anchor of FIGS. 3 to 5 to the nativemitral annulus;

FIG. 8 shows a cross-sectional view of a portion of a heart with thecoil anchor of FIGS. 3 to 5 positioned at the native mitral annulus;

FIG. 9 shows a cross-sectional view of a portion of a heart with thecoil anchor of FIGS. 3 to 5 and a prosthetic mitral valve implanted atthe native mitral annulus;

FIG. 10 shows a perspective view of a modified version of the coilanchor of FIGS. 3 to 5;

FIG. 11 schematically shows an open view of a laser-cut tube to be usedas a coil anchor according to an embodiment of the invention;

FIG. 11A schematically shows an open view of a laser-cut tube to be usedas a coil anchor and a tensioning wire according to an embodiment of theinvention;

FIG. 12 shows a top view of the laser-cut coil anchor of FIG. 11 in anassembled state;

FIG. 13 shows a perspective view of the laser-cut coil anchor of FIG. 11in an assembled and actuated state, and with the frame of a prostheticvalve held therein;

FIG. 14 shows a top view of a modified coil anchor with end hooks;

FIG. 15 shows a schematic view of another modified coil anchor with ahigh friction cover layer;

FIG. 16 shows a schematic view of yet another modified coil anchor withfriction elements;

FIG. 16A shows a cross-section view of the embodiment shown in FIG. 16;

FIG. 17 shows a schematic view of a coil anchor incorporating both ahigh friction covering and friction elements;

FIG. 18 shows still another modified coil anchor with surface featuresto facilitate interlocking or position retention between adjacent coils;

FIG. 19 shows an exemplary coil anchor that is a variation of the coilanchor of FIG. 10;

FIG. 19A shows a cross-section view of an embodiment of the coil anchor;

FIG. 20 schematically shows a top view of an embodiment of a coil anchorimplanted and arranged at a desired position at the native mitralannulus;

FIG. 21 shows the coil anchor of FIG. 19 further including marker bands;

FIG. 22 shows a cross-section of a proximal end of the coil anchor ofFIG. 19;

FIG. 22A shows an embodiment of a suture looped through a coiled anchor;

FIG. 22B shows another embodiment of a suture looped through a coiledanchor;

FIG. 22C shows an embodiment of a suture looped through a coiled anchor;

FIG. 23 shows a distal end of a coil skeleton or core of a dockingdevice according to an embodiment of the invention;

FIG. 24 shows a distal end of a coil skeleton or core of a dockingdevice according to another embodiment of the invention;

FIG. 25 shows a proximal end of a coil skeleton or core of a dockingdevice according to an embodiment of the invention; and

FIG. 26 shows a proximal end of the docking device of FIG. 25, with acover layer attached over the coil skeleton or core.

DETAILED DESCRIPTION

Disclosed herein are various coiled anchoring or docking devices, whichcan be used in conjunction with expandable transcatheter heart valves(THV) at a native valve annulus (e.g., mitral or tricuspid valveannulus), in order to more securely implant and hold the prostheticvalve at the implant site. Anchoring/docking devices according toembodiments of the invention provide or form a more circular and/orstable annulus at the implant site, in which prosthetic valves havingcircular or cylindrically-shaped valve frames or stents can be expandedor otherwise implanted. In addition to providing an anchoring site forthe prosthetic valve, the anchoring/docking devices can be sized andshaped to cinch or draw the native valve (e.g., mitral, tricuspid, etc.)anatomy radially inwards. In this manner, one of the main causes ofvalve regurgitation (e.g., functional mitral regurgitation),specifically enlargement of the heart (e.g., left ventricle) and/orvalve annulus, and consequent stretching out of the native valve (e.g.,mitral) annulus, can be at least partially offset or counteracted. Someembodiments of the anchoring or docking devices further include featureswhich, for example, are shaped and/or modified to better hold a positionor shape of the docking device during and/or after expansion of aprosthetic valve therein. By providing such anchoring or dockingdevices, replacement valves can be more securely implanted and held atvarious valve annuluses, including at the mitral annulus which does nothave a naturally circular cross-section.

A coil-shaped anchor/docking device according to an exemplary embodimentof the invention is shown in FIGS. 3 to 5. FIG. 3 shows a perspectiveview of the anchor or docking device 1, FIG. 4 shows a side view of theanchor/docking device 1, and FIG. 5 shows a top view of theanchor/docking device 1.

The docking device 1 includes a coil with a plurality of turns extendingalong a central axis of the docking device 1. The coil can be continuousand can extend generally helically, with various differently sized andshaped sections, as described in greater detail below. The dockingdevice 1 shown in FIGS. 3 to 5 is configured to best fit at the mitralposition, but can be shaped similarly or differently in otherembodiments for better accommodation at other native valve positions aswell.

The docking device 1 includes a central region 10 with approximatelythree full coil turns having substantially equal inner diameters. Thecentral region 10 of the docking device 1 serves as the main landingregion or holding region for holding the expandable prosthetic valve orTHV when the docking device 1 and the valve prosthesis are implantedinto a patient's body. Other embodiments of the docking device 1 canhave a central region 10 with more or less than three coil turns,depending for example, on the patient's anatomy, the amount of verticalcontact desired between the docking device 1 and the valve prosthesis(e.g., THV), and/or other factors. The coils of the central region 10can also be referred to as the “functional coils,” since the propertiesof these coils contribute the most to the amount of retention forcegenerated between the valve prosthesis, the docking device 1, and thenative mitral leaflets and/or other anatomical structures.

Various factors can contribute to the total retention force between thedocking device 1 and the prosthetic valve held therein. A main factor isthe number of turns included in the functional coils, while otherfactors include, for example, an inner diameter of the functional coils,a friction force between the coils and the prosthetic valve, and thestrength of the prosthetic valve and the radial force the valve applieson the coil. A docking device can have a variety of numbers of coilturns. The number of functional turns can be in ranges from just over ahalf turn to 5 turns, or one full turn to 5 turns, or more. In oneembodiment with three full turns, an additional one half turn isincluded in the ventricular portion of the docking device. In anotherembodiment, there can be three full turns total in the docking device.In one embodiment, in the atrial portion of the docking device, therecan be one-half to three-fourths turn or one-half to three-fourths of acircle. While a range of turns is provided, as the number of turns in adocking device is decreased, the dimensions and/or materials of the coiland/or the wire that the coil is made from can also change to maintain aproper retention force. For example, the diameter of the wire can belarger and/or the diameter of the function coil turn(s) in a dockingdevice with fewer coils. There can be a plurality of coils in the atriumand in the ventricle.

A size of the functional coils or coils of the central region 10 isgenerally selected based on the size of the desired THV to be implantedinto the patient. Generally, the inner diameter of the functionalcoils/turns (e.g., of the coils/turns of the central region 10 of thedocking device 1) will be smaller than the outer diameter of theexpandable heart valve, so that when the prosthetic valve is expanded inthe docking device, additional radial tension or retention force willact between the docking device and the prosthetic valve to hold theprosthetic valve in place. The retention force needed for adequateimplantation of a prosthetic valve varies based on the size of theprosthetic valve and on the ability of the assembly to handle mitralpressures of approximately 180 mm Hg. For example, based on benchtopstudies using a prosthetic valve with a 29 mm expanded outer diameter, aretention force of at least 18.5 N is needed between the docking deviceand the prosthetic valve in order to securely hold the prosthetic valvein the docking device and to resist or prevent mitral regurgitation orleakage. However, under this example, to meet this 18.5 N retentionforce requirement with statistical reliability, a target averageretention force should be substantially greater, for example,approximately 30 N.

In many embodiments, the retention force between the docking device andthe valve prosthesis reduces dramatically when a difference between theouter diameter of the prosthetic valve in its expanded state and theinner diameter of the functional coils is less than about 5 mm, sincethe reduced size differential would be too small to create sufficientretention force between the components. For example, when, as in oneembodiment, a prosthetic valve with a 29 mm expanded outer diameter isexpanded in a set of coils with a 24 mm inner diameter, the retentionforce observed is about 30 N, but when the same prosthetic valve isexpanded in a set of coils with a 25 mm inner diameter (e.g., only 1 mmlarger), the retention force observed drops significantly to only 20 N.Therefore, for valves and docking devices of this type, in order tocreate a sufficient retention force between the docking device and a 29mm prosthetic valve, the inner diameter of the functional coils (e.g.,the coils of the central region 10 of docking device 1) should be 24 mmor less. Generally, the inner diameter of the functional coils (e.g.,central region 10 of the docking device 1) should be selected to be atleast about 5 mm less than the prosthetic valve that is selected forimplantation, though other features and/or characteristics (e.g.,friction enhancing features, material characteristics, etc.) can be usedto provide better retention if other sizes or size ranges are used, asvarious factors can affect retention force. In addition, a size of theinner diameter of the functional coils or central region 10 can also beselected to draw the mitral anatomy closer together, in order to atleast partially offset or counteract mitral regurgitation that is causedby stretching out of the native valve annulus as a result of, forexample, left ventricular enlargement.

It is noted that the desired retention forces discussed above areapplicable to embodiments for mitral valve replacements. Therefore,other embodiments of the docking device that are used for replacement ofother valves can have different size relationships based on the desiredretention forces for valve replacement at those respective positions. Inaddition, the size differentials can also vary, for example, based onthe materials used for the valve and/or the docking device, whetherthere are any other features to prevent expansion of the functionalcoils or to enhance friction/locking, and/or based on various otherfactors.

In embodiments where the docking device 1 is used at the mitralposition, the docking device can first be advanced and delivered to thenative mitral valve annulus, and then set at a desired position, priorto implantation of the THV. Preferably, the docking device 1 is flexibleand/or made of a shape memory material, so that the coils of the dockingdevice 1 can be straightened for delivery via a transcatheter approachas well. In another embodiment, the coil can be made of anotherbiocompatible material, such as stainless steel. Some of the samecatheters and other delivery tools can be used for both delivery of thedocking device 1 and the prosthetic valve, without having to performseparate preparatory steps, simplifying the implantation procedure forthe end user.

The docking device 1 can be delivered to the mitral positiontransatrially from the left atrium, transseptally through the atrialseptum, or can be delivered to the mitral position via one of variousother known access points or procedures. FIGS. 6 and 7 illustrate somesteps during delivery of a docking device 1 to the mitral position usinga transseptal approach, where a guide sheath 1000 is advanced throughvasculature to the right atrium and through the atrial septum of theheart to the left atrium, and a delivery catheter 1010 is advancedthrough the guide sheath 1000 passing through the vasculature, rightatrium, and septum into the left atrium. As can best be seen in FIG. 6,the docking device 1 can be advanced through a distal end of thedelivery catheter 1010 positioned in the left atrium (e.g., positionedat a commissure), through the native mitral annulus, for example, at acommissure of the native mitral valve, and into the left ventricle. Thedistal end of the docking device 1 then circles around the mitralanatomy (e.g., native mitral leaflets and/or the chordae tendineae)located in the left ventricle, so that all or at least some of thenative leaflets and/or the chordae tendineae are corralled or gatheredby and held in (e.g., encircled by) the coils of the docking device 1.

However, since the functional coils/turns or coils/turns of the centralregion 10 of the docking device 1 are kept relatively small in diameter(e.g., the central region 10 in one embodiment can have an innerdiameter of approximately 24 mm (e.g., ±2 mm) or another diametersmaller than the THV and/or the native annulus) in order to increaseretention force with the prosthetic valve, it might be difficult toadvance the docking device 1 around the existing leaflets and/or chordaeto a desired position relative to the native mitral annulus. This isespecially true, if the entire docking device 1 is made to have the samesmall diameter as the central region 10. Therefore, referring back toFIGS. 3 to 5, the docking device 1 can have a distal or lower region 20that makes up a leading coil/turn (or leading ventricular coil/turn) ofthe docking device 1, which has a diameter that is greater than thediameter of the functional coils/turns or of the coils/turns of centralregion 10.

Features of the mitral anatomy in the left ventricle have variabledimensions, and can have an approximately 35 mm to 45 mm greatest widthon a long axis. The diameter or width of the leading coil/turn (e.g.,ventricular coil/turn) of the lower region 20 can therefore be selectedto be larger to more easily navigate a distal or leading tip 21 of thedocking device 1 around and encircle the features of the mitral anatomy(e.g., leaflets and/or chordae tendineae). Various sizes and shapes arepossible, for example, in one embodiment, the diameter could be any sizefrom 25 mm to 75 mm. The term “diameter” as used in this disclosure doesnot require that a coil/turn be a complete or perfectly-shaped circle,but is generally used to refer to a greatest width across opposingpoints of the coil/turn. For example, with respect to the leadingcoil/turn, diameter can be measured from the distal tip 21 to theopposite side, as if the lower region 20 or leading coil/turn formed acomplete rotation, or the diameter can be considered double a radius ofcurvature of the leading coil/turn. In one embodiment, the lower region20 of the docking device 1 (e.g., the leading coil/turn) has a diameter(e.g.) of approximately 43 mm (e.g., ±2 mm), in other words the radiusof curvature at the leading coil/turn can be approximately 21.5 mm.Having a leading coil/turn with a larger size than the functional coilscan help more easily guide the coils around and/or through the chordaegeometry, and most importantly, adequately around both native leafletsof the mitral valve. Once the distal tip 21 is navigated around thedesired mitral anatomy, the remaining coils of the docking device 1 canalso be guided around the same features, where the reduced size of theother coils can cause the corralled anatomical features to be pulledslightly radially inwardly. Meanwhile, the length of the enlarged lowerregion 20 is generally kept relatively short, to prevent or avoidobstruction or interference of the flow of blood along the leftventricular outflow tract by the lower region 20. For example, in oneembodiment, the enlarged lower region 20 extends for only about half aloop or rotation. With a lower region 20 having this relatively shortlength, when a prosthetic valve is expanded into the docking device 1and the coils of the docking device 1 start to unwind slightly due tothe size differential between the docking device and the prostheticvalve, the lower region 20 may also be drawn in and shift slightly.Under this example, after expansion of the prosthetic valve, the lowerregion 20 can be similar in size and be aligned substantially with thefunctional coils of the docking device 1, rather than continuing toproject away from the functional coils, thereby reducing any potentialflow disturbances. Other docking device embodiments can have lowerregions that are longer or shorter, depending on the particularapplication.

The docking device 1 in FIGS. 3 to 5 also includes an enlarged proximalor upper region 30 that makes up a stabilizing coil/turn (e.g., whichcan be an atrial coil/turn) of the docking device 1. When the dockingdevice 1 has been placed in a desired position and orientation at thenative mitral annulus, the entire docking device 1 is released from thedelivery catheter 1010, and thereafter a prosthetic valve (e.g., a THV)is delivered to the docking device 1. During a transient or intermediatestage of the implantation procedure, that is, during the time betweenthe deployment and release of the docking device 1 and final delivery ofthe prosthetic valve, there is a possibility that the coil could beshifted and/or dislodged from its desired position or orientation, forexample, by regular heart function. Shifting of the docking device 1could potentially lead to a less secure implantation, misalignment,and/or other positioning issues for the prosthetic valve. Astabilization feature or coil can be used to help stabilize the dockingdevice in the desired position. For example, the docking device 1 caninclude the upper region 30 with an enlarged stabilization coil/turn(e.g., an enlarged atrial coil/turn) intended to be positioned in thecirculatory system (e.g. in the left atrium) such that it can stabilizethe docking device. For example, the upper region 30 or stabilizationcoil/turn can be configured to abut or push against the walls of thecirculatory system (e.g., against the walls of the left atrium), inorder to improve the ability of the docking device 1 to stay in itsdesired position prior to the implantation of the prosthetic valve.

The stabilization coil/turn (e.g., atrial coil/turn) at the upper region30 of the docking device 1 in the embodiment shown extends for about ornearly one full turn or rotation, and terminates at a proximal tip 31.In other embodiments, the stabilization coil/turn (e.g., atrial coil)can extend for more or less than one turn or rotation, depending forexample on the amount of contact desired between the docking device andthe circulatory system (e.g., with the walls of the left atrium) in eachparticular application. The radial size of the stabilization coil/turn(e.g., atrial coil) at the upper region 30 can also be significantlylarger than the size of the functional coils in the central region 10,so that the stabilization coil/turn (e.g., atrial coil) flares orextends sufficiently outwardly in order to make contact with the wallsof the circulatory system (e.g., the walls of the left atrium). Forexample, in one embodiment, a major diameter 32 or width of the upperregion 30 is approximately 50 mm (e.g., ±2 mm), or about twice as largeas the coils in the central region 10. A bottom region of the leftatrium generally narrows towards the native mitral annulus. Therefore,when the docking device 1 is properly deployed at the mitral position,the stabilization coil/turn (e.g., atrial coil) of the upper region 30sits and pushes against the walls of the left atrium, to help keep orhold the docking device 1 at a relatively high desired position andorientation, and preventing or reducing shifting of the docking device 1towards the left ventricle, until the THV is advanced to and expanded inthe docking device 1. Once the prosthetic valve (e.g., THV) is expandedwithin the docking the device, the force generated between thefunctional coils and prosthetic valve (e.g., with tissue, leaflets, etc.therebetween) is sufficient to secure and stabilize the docking deviceand prosthetic valve without needing the stabilization coil/turn.

Optionally, the stabilization coil/turn (e.g., atrial coil) of the upperregion 30 can be non-circular in shape, and in the embodiment shown, isbiased and arranged in an elliptical or ovoid shape. As illustrated inFIG. 5, an elliptical or other non-circular shape stabilizationcoil/turn (e.g., atrial coil) can have a major axis diameter 32, D₁(i.e., a greatest width of the coil turn) and a minor axis diameter 33,D₂ (i.e., a smallest end-to-end width). The widths/diameters can bechosen based on the size of the anatomy of a portion of a circulatorysystem (e.g., based on the size of human's left atrium). The major axisdiameter (or greatest width), D₁, can range from 40 to 100 mm, or can befrom 40-80, mm, or from 40-75 mm. The minor axis diameter (or smallestwidth) D₂ can range from 20 to 80 mm, or from 20 to 75 mm. While a majordiameter/width D₁ of the stabilization coil/turn (e.g., atrial coil) canbe approximately 50 mm, a diameter/width D₂ along a minor axis of thestabilization coil/turn (e.g., atrial coil) can be much smaller, forexample, only slightly larger than the diameter of the central region 10of the docking device 1, as can best be seen in the top view of thedocking device 1 in FIG. 5. In other embodiments, the biasing of theupper region of the docking device can be effected in other ways. Forexample, the stabilization coil/turn (e.g., atrial coil) of the upperregion 30 can still be substantially circular, and/or the stabilizationcoil/turn can be biased in one direction, such that a center of theupper region is offset from the center of other portions of the dockingdevice. This biasing of the shape of the upper region 30 of the dockingdevice 1 can, for example, increase contact between the docking device 1and the wall of the left atrium or other anatomy in the radial directionthat the upper region 30 extends farthest from other portions of thedocking device 1. The stabilization coil/turn (e.g., atrial coil) can bebiased such that when viewed from a bird's eye view (FIG. 20), thestabilization coil/turn (e.g., atrial coil) has a center that is offcenter from the center of the functional coils by about 50 to 75% of thediameter of the functional turns. The stabilization turn (e.g., atrialturn) of the coil can be compliant, and flex inwards. This accommodatesanatomy (e.g., left atrium anatomy) where the stabilization coil/turn(e.g., atrial coil) may have a major or minor axis diameter that islarger than the atrium or other anatomy itself.

Importantly, the docking device 1 can be rotated or otherwise orientedso that the narrower portion of the upper region 30, or the portion thatextends the least radially outwardly, is directed in an optimal way. Forexample, when implanted in a native mitral valve, towards the wall ofthe left atrium that opposes or pushes against the left ventricularoutflow tract, so that the amount of pressure applied by the dockingdevice 1 against that portion of the atrial wall is reduced. In thismanner, an amount of displacement of that portion of the wall into theleft ventricular outflow tract will also be reduced, and the enlargedupper region 30 can therefore avoid obstructing, interfering with, orotherwise affecting the blood flow through the left ventricular outflowtract.

With the enlarged upper region 30, the docking device 1 can be moresecurely held or retained at a proper positioning and orientation at thenative valve annulus (e.g., native mitral annulus) before the THV isimplanted and expanded therein. Such self-retention of the dockingdevice 1 will more effectively prevent undesirable shifting or tiltingof the docking device 1 before the prosthetic valve is fully implanted,thereby improving performance of the implant as a whole.

FIGS. 6 to 9 show some of the steps that can be used for delivering andimplanting a docking device (e.g., docking device 1 or other dockingdevices described elsewhere herein) and a THV at the mitral position.While these focus on the mitral position, similar steps can be used inother valve locations, e.g., at the tricuspid valve position. Thedocking device can be the docking device 1 described above with respectto FIGS. 3 to 5 or another similar docking device (e.g., other dockingdevices herein), and the THV is generally a self-expandable, amechanically expandable or a balloon expandable THV (or a combination ofthese) with a circular or cylindrical valve frame or stent that is sizedto be expanded and held in the docking device.

FIGS. 6 and 7 show a transseptal procedure for delivering the dockingdevice 1 to a patient's mitral position, where a guide sheath/introducer1000 is advanced across the atrial septum of the heart and a distal endof a delivery catheter 1010 is advanced through the guide sheath 1000and positioned with a distal opening of the delivery catheter positionedin the left atrium for delivering the docking device 1. Optionally, adelivery catheter can be similarly advanced through the anatomy (e.g.,vasculature, chambers of the hearth, septum, etc.) and similarlypositioned without first inserting or using a guide sheath. In anexample procedure, the guide sheath 1000 (and/or delivery catheter 1010)is introduced into the patient's venous system by percutaneous punctureor by a small surgical cut, for example, at the patient's groin, andthen the guide sheath 1000 (and/or catheter 1010) is advanced throughthe patient's vasculature to the left atrium as shown in FIGS. 6 and 7.It is noted that the transseptal procedure illustrated is only oneexample, and various alternative procedures and/or access sites caninstead be used for delivering the docking device 1 and/or a suitableprosthetic valve to either the mitral position or to other positions ofthe heart. However, a transatrial or transseptal procedure may bepreferable, because such procedures provide a cleaner entry into theleft side of the heart when compared, for example, to a transapicalprocedure or other procedure where access to the mitral valve is via theleft ventricle, so that the practitioner can avoid direct interferencewith the chordae tendineae and other ventricular obstacles.

As shown in FIG. 6, the delivery catheter 1010 is advanced to a positionin the left atrium where the distal end of the delivery catheter 1010 isjust above a plane of the native valve (e.g., the mitral plane) and canbe positioned, for example, near a commissure of the native valve. Thedelivery catheter can be steerable in multiple dimensions (e.g., morethan two dimensions) to allow more precise positioning. The positioningof the distal opening of the delivery catheter defines an access sitefor implanting the docking device 1 at the mitral position. The accesssite is usually near one of the two commissures of the native mitralvalve, so that the leading tip 21 of the docking device 1 can beadvanced through the native valve commissure into the left ventricle, inorder to deploy the leading coil/turn (e.g., ventricular coil) of thelower region 20, as well as at least part of the functional coils (e.g.,coils of the central region 10), into the left ventricle. In onedeployment method, the leading tip 21 of the docking device 1 is firstpassed through commissure A3P3 of the native mitral valve, and then moreof the docking device 1 is advanced out of the delivery catheter throughcommissure A3P3.

While the docking device 1 is held in the delivery catheter 1010, thedocking device 1 can be straightened to be more easily maneuveredthrough the delivery catheter 1010. Thereafter, as the docking device 1is rotated, pushed or otherwise advanced out of the delivery catheter1010, the docking device 1 can return to its original coiled or curvedshape, and further advancement of the docking device 1 out of thedelivery catheter causes either a clockwise or a counter-clockwise(i.e., viewing the annulus in the direction of blood outflow)advancement of the leading tip 21 around (e.g., to encircle) variousfeatures of the mitral anatomy, based on the direction of curvature ofthe docking device 1 when it exits the delivery catheter. The enlargedleading coil/turn (e.g., ventricular coil/turn) at the lower region 20of the docking device 1 makes navigating the leading tip 21 of thedocking device 1 around the mitral anatomy in the left ventricle easier.In the above example, when the leading tip 21 of the docking device 1enters the left ventricle through commissure A3P3 and is advancedclockwise viewing the annulus in the outflow direction (e.g., fromatrium to ventricle), the docking device 1 can first go around andcorral the posterior leaflet of the native mitral valve. Alternativemethods are also available for corralling the posterior leaflet first,for example, by inserting the leading tip 21 through commissure A1P1 andthen advancing the docking device counter-clockwise.

In some situations, corralling of the posterior leaflet of the nativemitral valve first may be easier than corralling of the anterior leafletfirst, because the posterior leaflet is positioned closer to aventricular wall that provides for a more confined space along which theleading tip 21 can advance. The leading tip 21 of the docking device 1can therefore use the ventricular wall near the posterior leaflet as apathway or guide for advancement around the posterior leaflet.Conversely, when trying to advance the leading tip 21 of the dockingdevice 1 around and to capture the anterior leaflet of the native mitralvalve first, there is no ventricular wall nearby that can facilitate orguide the advancement of the leading tip 21 in that direction.Therefore, in some situations, it can be more difficult to properlyinitiate the encircling of the mitral anatomy when navigating theleading tip 21 to try to first capture the anterior leaflet instead ofthe posterior leaflet.

With that said, it can still be preferential or required in someprocedures to corral the anterior leaflet first. In addition, in manysituations, it can also be much simpler to bend the distal end of thedelivery catheter 1010 in a counter-clockwise direction in preparationfor delivery of the docking device. As such, the delivery method of thedocking device can be adjusted accordingly. For example, a dockingdevice can be configured with coil turns in an opposite,counter-clockwise direction (e.g., as seen in FIG. 10 below), where thedelivery catheter 1010 also winds in a counter-clockwise direction. Inthis manner, such a docking device can be advanced, for example, throughcommissure A3P3 and into the left ventricle in a counter-clockwisedirection viewing the annulus in an outflow (e.g., atrium to ventricle)direction instead of in the clockwise direction described above.

An amount of the docking device to be advanced into the left ventricledepends on the particular application or procedure. In one embodiment,the coil(s) of the lower region 20, and most of the coils of the centralregion 10 (even if not all) are advanced and positioned in the leftventricle. In one embodiment, all of the coils of the central region 10are advanced into the left ventricle. In one embodiment, the dockingdevice 1 is advanced to a position where the leading tip 21 sits behindthe anterior medial papillary muscle. This position provides a moresecure anchoring of the leading tip 21, and consequently of the dockingdevice 1 as a whole, because the leading tip 21 sits and is held betweenthe chordae tendineae and the ventricular wall in that area. Meanwhile,once any part of the mitral anatomy is corralled and/or captured by theleading tip 21, further advancement of the docking device 1 serves togather the captured chordae and or leaflets within the coils of thedocking device 1. Both the secure positioning of the leading tip 21 andthe holding of the native mitral anatomy by the docking device 1 canserve to prevent obstruction of the left ventricular outflow tract(e.g., of the aortic valve) prior to implantation of the THV.

After a desired amount of the docking device 1 has been advanced intothe left ventricle, the rest of the docking device 1 is then deployed orreleased into the left atrium. FIG. 7 shows one method of releasing theatrial portion of the docking device 1 into the left atrium. In FIG. 7,the distal end of the delivery catheter 1010 is rotated backwards orretracted, while the docking device 1 remains in substantially the sameposition and orientation, until the entire docking device 1 is releasedfrom the delivery catheter 1010. For example, when the docking device 1is advanced clockwise through commissure A3P3, the distal end of thedelivery catheter 1010 can thereafter be rotated counter-clockwise orretracted for releasing the atrial portion of the docking device 1. Inthis manner, a ventricular position of the docking device 1 does nothave to be adjusted or readjusted during or after releasing the atrialportion of the docking device 1 from the delivery catheter 1010. Variousother methods of releasing the atrial portion of the docking device 1can also be employed. Prior to releasing the stabilization coil/turn(e.g., atrial coil) from the delivery catheter, it can be held in placeand/or retracted/retrieved by a holding device/anchor (e.g., by beinghooked to a release suture, connected by a barb, a Velcro hook, a latch,a lock, an anchor that can screw in to the delivery device, etc.). Oncereleased, the docking device is not tightly engaged with the nativemitral valve (i.e., it is only loosely positioned around the nativemitral valve leaflets).

After the docking device 1 is fully deployed and adjusted to a desiredposition and orientation, the delivery catheter 1010 can be removed tomake room for a separate delivery catheter for delivering the THV, or insome embodiments, the delivery catheter 1010 can be adjusted and/orrepositioned if the prosthetic valve is to be delivered through the samecatheter 1010. Optionally, the guide sheath 1000 can be left in placeand the prosthetic valve or THV delivery catheter can be inserted andadvanced through the same guide sheath 1000 after the delivery catheter1010 is removed. FIG. 8 shows a cross-sectional view of a portion of apatient's heart with the docking device 1 of FIGS. 3 to 5 positioned atthe mitral position and prior to delivery of the THV. Here, the enlargedupper region 30 of the docking device 1 can push against the atrialwalls to help hold the docking device 1 in the desired orientation, andas described above, the biasing of the upper region 30 can be arrangedso that the upper region 30 does not push against any walls that couldpotentially lead to obstructions in the left ventricular outflow tract.

In addition, it should be noted that in at least some procedures, oncethe docking device 1 is delivered to the mitral position as describedabove, and prior to implantation of the prosthetic valve therein, thenative mitral valve can still continue to operate substantiallynormally, and the patient can remain stable, since the valve leafletsare not substantially restrained by the docking station. Therefore, theprocedure can be performed on a beating heart without the need for aheart-lung machine. Furthermore, this allows the practitioner more timeflexibility to implant the valve prosthesis, without the risk of thepatient being in or falling into a position of hemodynamic compromise iftoo much time passes between the implantation of the docking device 1and the later valve implantation.

FIG. 9 shows a cross-sectional view of a portion of the heart with boththe docking device 1 and a prosthetic valve 40 (e.g., THV) finallyimplanted at the mitral position. Generally, the prosthetic valve 40will have an expandable frame structure 41 that houses a plurality ofvalve leaflets 42. The expandable frame 41 of the prosthetic valve 40can be balloon expandable, or can be expanded in other ways, forexample, the frame can be self-expanding, mechanically-expanding, orexpandable in a combination of ways. The prosthetic valve 40 can bedelivered through the same catheter 1010 used to deliver the dockingdevice 1, or can be introduced through a separate catheter, generallywhile the valve 40 is radially collapsed for easier navigation throughthe delivery catheter. Optionally, the guide sheath can be left in placewhen catheter 1010 is removed, and a new prosthetic valve or THVdelivery catheter can be advanced through guide sheath 1000. Theprosthetic valve 40 is then advanced out of the delivery catheter andpositioned through the docking device 1 while still in the collapsedconfiguration, and can then be expanded in the docking device 1, so thatthe radial pressure or tension between the components securely hold theentire assembly in place at the mitral position. The mitral valveleaflets (or a portion of the mitral valve leaflets) can be sandwichedbetween the functional turns of the docking coil and the frame 41 of theprosthetic valve. After the docking device and prosthetic valve aresecurely deployed/implanted, the remaining delivery tools can be removedfrom the patient.

FIG. 10 shows a perspective view of a modified version of the coilanchor or docking device 1 of FIGS. 3 to 5. The docking device 100 inFIG. 10 has a central region 110, a lower region 120, and an upperregion 130 that can be the same as or similar to the respective central,lower, and upper regions 10, 20, 30 in the previously described dockingdevice 1. The docking device 100 can include features andcharacteristics that are the same as or similar to features andcharacteristics described with respect to docking device 1, and can alsobe implanted using the same or similar steps. However, the dockingdevice 100 includes an additional extension 140 substantially positionedbetween the central region 110 and upper region 130. In someembodiments, the extension 140 can optionally be positioned, forexample, wholly in the central region 110 (e.g., at an upper portion ofthe central region 110) or wholly in the upper region 130. In FIG. 10,the extension 140 is made up of or includes a vertical part of the coilthat extends substantially parallel to a central axis of the dockingdevice 100. In some embodiments, the extension 140 can be angledrelative to the central axis of the docking device 100, but willgenerally serve as a vertical or axial spacer that spaces apart theadjacent connected portions of the docking device 100 in a vertical oraxial direction, so that a vertical or axial gap is formed between thecoil portions on either side of the extension 140 (e.g., a gap can beformed between an upper or atrial side and a lower or ventricular sideof the docking device 100).

The extension 140 of the docking device 100 is intended to be positionedthrough (e.g., crossing) or near the native valve annulus, in order toreduce the amount of the docking device 100 that passes through orpushes or rests against the native annulus when the docking device 100is implanted. This could potentially reduce the stress or strain appliedby the docking device 100 on the native mitral valve. In onearrangement, the extension 140 is positioned at and passes through orcrosses at one of the commissures of the native mitral valve. In thismanner, the extension 140 can space the upper region 130 apart fromnative mitral leaflets to prevent the upper region 130 from interactingwith or engaging the native leaflets from the atrial side. The extension140 also raises a position of the upper region 130, so that the contactthat the upper region 130 makes against the atrial wall can be elevatedor spaced farther away from the native valve, which could, for example,also reduce stresses on and around the native valve, as well as providefor a more secure holding of the position of the docking device 100. Theextension 140 can have a length ranging from 5 to 100 mm, and in oneembodiment is 15 mm.

The docking device 100 can further include one or more through holes 150at or near one or both of the proximal and distal ends of the dockingdevice 100. The through holes 150 can serve, for example, as suturingholes for attaching a cover layer over the coil of the docking device100, and/or for example, as an attachment site for delivery tools, suchas a pull wire/suture for a pusher, a holding device/anchor (e.g., forholding the docking device and/or allowing retraction and retrievabilityof the device after being fully or partially deployed from the deliverycatheter), or other advancement device or retention device. In someembodiments, a width or thickness of the coil of the docking device 100can also be varied along the length of the docking device 100. Forexample, a central region of the docking device 100 can be made slightlythinner than end regions of the docking device 100 (not shown), so thatfor example, the central regions exhibit greater flexibility, the endregions are stronger or more robust, and/or the end regions provide moresurface area for suturing or otherwise attaching a cover layer to thecoil of the docking device 100, among other reasons. In one embodiment,all or a portion of extension 140 can have a thickness that is less thanthe thickness in other regions of the docking device, e.g., extension140 can be thinner than the leading coil/turn or lower region 120,thinner than the functional coils/turns or central region 110, and/orthinner than the stabilization coil/turn or upper region 130, e.g., asshown, for example, in FIG. 19.

In FIG. 10 (and similarly FIG. 19), the coils of the docking device 100are depicted as turning in a direction opposite to the coils in thedocking device 1 described above. Therefore, the docking device 100, asdepicted, is configured to be inserted through the native valve annulusin a counter-clockwise direction viewing the annulus in the direction ofblood outflow (e.g., from atrium to ventricle). This advancement can bemade through commissure A3P3, commissure A1P1, or through another partof the native mitral valve. Arrangement of the docking device 100 in acounter-clockwise direction also allows for bending of the distal end ofthe delivery catheter in a similar counter-clockwise direction, which inmany instances is easier to achieve than to bend the delivery catheterin the clockwise direction. The various coiled docking deviceembodiments described herein (including docking devices 1, 100, 200,300, 400, 500, 600, and 1100) can be configured for either clockwise orcounter-clockwise advancement through one of various access points(e.g., either commissure).

In most situations and patients, the docking device should be placedhigh relative to the native mitral valve (e.g., farther into the leftatrium). When considering the mitral anatomy, the finally implanted dockand valve combination should be placed high at the native valve, in somecases as high as possible, to anchor the valve to a clear zone of thenative mitral leaflets. In addition, in a healthy human heart, thenative mitral leaflets are generally smoother above the coaptation line(e.g., above where the leaflets come together when the mitral valve isclosed) and rougher below the coaptation line. The smoother area or zoneof the native leaflets are much more collagenous and stronger, therebyproviding a more secure anchoring surface for the prosthetic valve thanthe rougher area or zone. Therefore, in most cases, the docking deviceshould be placed as high as possible at the native valve duringinsertion, while also having sufficient retention force to anchor theprosthetic valve or THV. For example, the length of the coil in thedocking device placed in the ventricle generally depends on the numberof turns in the ventricle and the thickness of the wire used. Generally,the thinner the wire used, the more length is required in the ventricleto provide sufficient retention force. For example, if a docking devicecoil has a length of 370 mm, then about 280 mm (e.g., ±2 mm) would beplaced in the ventricle. About 70 to 90 mm would be placed in theatrium, and about 10-15 would be used in the transition or extensionlength to move the docking device coils away from the plane of themitral valve on the atrial side of the docking device.

The average mitral valve in humans measures approximately 50 mm alongits long axis and 38 mm along its short axis. Due to the size and shapeof the native valve and the typically smaller size of replacementvalves, an inverse relationship is formed with respect to the coildiameter of the docking device between how high the docking device canbe placed at the mitral position and the retention force the dockingdevice can provide for the THV to be implanted therein. Docking deviceswith larger diameters are able to capture more chordae therein andconsequently have the ability to be deployed higher relative to thenative valve, but will provide a lower amount of retention force forvalves that are docked in them. Conversely, docking devices with smallerdiameters can provide stronger retention forces for docked valves, butmay not be able to go around and capture as many chordae duringpositioning, which can result in lower positioning of the docking devicein the native valve annulus. Meanwhile, larger docking devices can bemodified so that they have increased coil diameters or thicknessesand/or can be constructed using materials with higher moduli ofelasticity.

FIGS. 11 to 13 show a docking device according to another embodiment ofthe invention. The docking device 200 (see FIGS. 12 and 13) is formedwith a laser-cut tube 210 and a tensioning wire 219. The wire 219 can beused to adjust the curvature and/or size of the docking device 200. Forexample, the docking device 200 can assume a larger or widerconfiguration when being positioned at the native valve annulus, and canthereafter be adjusted with the wire 219 to assume a smaller or narrowerconfiguration to prepare for docking a prosthetic valve.

FIG. 11 schematically shows an open sheet view of a laser-cut tube 210,e.g., the ends of the sheet can be connected to form a tubularstructure, or a similar tube can be formed as a tube and cut as a tube,i.e., without a seam. The tube 210 can be made from either shape memoryor non-shape memory material (e.g., NiTi, stainless steel, othermaterials, or a combination of materials). The tube 210 can be laser cutwith the pattern shown in FIG. 11, or with a similar pattern, where thecutting pattern dictates the shape of the docking device 200 when thedocking device 200 is actuated. The patterned cuts in FIG. 11 include aplurality of separate cuts 211 that extend transversely to alongitudinal axis of the tube 210, and that separate the tube 210 into aplurality of interconnected links 212. Each of the cuts 211 can furtherform one or more teeth 213 and one or more corresponding grooves 214 inadjacent links 212, where the teeth 213 can extend into the adjacentgrooves 214, including when the tube 210 is bent or curved. The teeth213 and grooves 214 formed by each cut 211 can extend in a samedirection along the tube 210, or some can be configured to extend in theopposite direction, depending on the desired shape of the docking device200. The cuts 211 are also wholly contained on the sheet or tube, inother words, the cuts 211 do not extend to any of the edges of the tubesheet or tube, so that the links 212 remain interconnected with oneanother at least at one region. In other embodiments, some or all of thecuts can extend to the edges of the sheet or tube, as needed. In theembodiment of FIG. 11, each of the cuts 211 further include end regions215 on either end of the cuts 211 that extend parallel to thelongitudinal axis of the tube 210. The end regions 215 provide space foradjacent links 212 to pivot relative to one another while remaininginterconnected.

The laser-cut patterning can also be modified or varied along the lengthof the tube 210, with cuts having different sizes, shapes, andpositioning on the sheet or tube, in order to effect different shapesand curvatures in the docking device 200 when the docking device 200 istensioned or actuated. For example, as seen in FIG. 11, a left end ofthe sheet or tube includes other cuts 216 that are larger than cuts 211that are found at the central and right portions of the sheet or tube(as illustrated). The left end of the tube 210 can have such enlargedlaser cut patterns in order to effect a more mobile or flexible distaltip of the docking device 200, as described in greater detail below.

In addition, the laser-cut sheet or tube can include one or more distalwire lock features, for example, cut 217 at a distal or left end of thesheet or tube as illustrated, and/or one or more proximal wire lockfeatures, for example, cuts 218 at the proximal or right end of thesheet or tube as illustrated. Using one or both of the distal 217 orproximal 218 wire lock features, a locking wire 219, illustrated in FIG.11A, can be attached to the distal or proximal end of the tube 210, andcan then be tensioned through the tube 210 and locked at the oppositeend of the tube 210 in order to effect a desired actuated shape of thedocking device 200. By having laser cut patterns positioned along alarge portion of or along the entire length of the tube 210, when thelocking wire 219 is attached at one end of the tube 210 and is thenactuated and locked to the other end of the tube 210, the tube 210 isforced into a desired final coil form or shape by virtue of thearrangement of the cuts 211 and 216. The tension in the tensioning wirehas the ability to control the radial outward and inward forces appliedonto the docking device 200, and by the docking device 200 onto otherfeatures, for example, on a replacement valve 40 held therein. Thelocking wire can assist in controlling the forces applied by the dockingdevice, but in other embodiments, a locking wire is not required. Thelocking wire can be in a laser-cut hypotube, or the locking wire can bein a tube that is not laser cut. The locking wire can be a suture,tether, wire, strip, etc., and the locking wire can be made of a varietyof materials, e.g., metal, steel, NiTi, polymer, fiber, Dyneema, otherbiocompatible materials, etc.

In some embodiments, for example, embodiments where a shape memorymaterial, such as NiTi, is used to construct the docking device 200, thetube 210 can be placed around a round mandrel defining a desired coildiameter during manufacture and shape set at that specific diameter. Theshape set diameter can in some embodiments be larger than the desiredfinal diameter of the docking device 200, so that the tube 210 assumesthe larger shape set diameter when it is extruded from a deliverycatheter and prior to the locking or tensioning wire being actuated.During this time, the larger diameter of the docking device 200 can helpassist the docking device 200 in more easily navigating around andencircling the anatomical geometry of the native valve.

Furthermore, in some embodiments, the distal tip 222 of the tube 210 canbe shape set differently, so that instead of following the same coilshape as the rest of the docking device 200, the distal tip 222 flexesor articulates slightly radially outwardly compared to other portions ofthe docking device 200, for example, as can be seen in FIG. 12, in orderto further assist in helping to encircle the mitral anatomy or othervalve anatomy. In addition to or in lieu of a different shape setting,as mentioned above, the distal end 222 of the tube 210 can includedifferent cuts 216 in order to make the distal end 222 more flexible ormobile, which can also assist in navigating the distal end 222 of thedocking device 200 around the anatomical geometry.

After the docking device 200 has been maneuvered around the mitralanatomy or other anatomical geometry and has reached a desired positionrelative to the native valve, the locking wire can be tensioned orotherwise actuated in order to reduce the size of the docking device(e.g., to reduce the diameter of the turns of the coil), in preparationfor a tighter or more secure docking of a prosthetic replacement valve40. Meanwhile, in some embodiments where the distal tip 222 of thedocking device 200 is shape set to flex outwards, the tensioning of thelocking wire can in some cases draw or pull the distal tip 222 furtherinwards such that the distal tip 222 conforms more closely in shape tothe rest of the docking device 200, to more effectively contribute tothe docking of the replacement valve 40.

Thereafter, the replacement valve 40 can be positioned and expanded inthe docking device 200. FIG. 13 is an example of the docking device 200after it has been actuated by the locking wire, and also after thereplacement valve 40 has been expanded therein. The tension in thelocking wire helps to more effectively hold a desired shape and size ofthe docking device 200 and to maintain a stronger retention forcebetween the docking device 200 and the valve 40. The radial outwardpressure provided by the valve 40 on the docking device 200 is counteredby the radial inward pressure provided by the tensioning or locking wireand docking device 200 onto the valve 40, forming a stronger and moresecure hold between the pieces. As can further be seen in FIG. 13, sincethe docking device 200 can more effectively hold its shape and size, theradial inward pressure from the docking device 200 on the valve 40 cancause a flaring effect at the ends of the frame of the valve 40, therebyproviding an even more secure hold between the docking device 200 andthe valve 40.

The docking device 200 can be modified in various ways in otherembodiments. For example, the docking device can be made from or includeshape memory materials other than NiTi, or in some embodiments can bemade from non-shape memory materials, such as stainless steel, fromother biocompatible materials, and/or a combination of these. Inaddition, while the docking device 200 has been described above for useat the mitral valve, in other applications, a similar or slightlymodified docking device can also be used to dock replacement valves atother native valve sites, for example, at the tricuspid valve, pulmonaryvalve, or at the aortic valve.

The docking device 200 described above, and similar devices using atensioning or locking wire, can provide several advantages over otherdocking devices, such as devices where a locking wire is not used. Forexample, the locking wire provides a user with the ability to control anamount of the radial outward and inward forces applied on and by thedocking device through effecting and adjusting the tension in thelocking wire, without compromising a desired profile of the dockingdevice or the ability to deliver the docking device through a catheteror via minimally invasive techniques. FIG. 11A illustrates a tensioningwire 219 that is held below the teeth 218 or looped around teeth 218,then pulled through the opening 217 and crimped at the opening 217 toset the shape of the docking device. In addition, the laser cuts in thetube make the docking device more flexible, enabling the docking deviceto be introduced through catheters that may have relatively small bendradii at certain locations.

In embodiments where a shape memory material is used, the docking devicecan be shape set to a coil having a larger diameter to allow the coil tomore easily encircle anatomical features during delivery of the dockingdevice and prior to the locking wire being tensioned. In addition, thedistal tip of the docking device can further be shape set to flex orbias slightly outwards to help encircle even more of the anatomicalgeometry during advancement and positioning of the docking device. Inaddition, in some embodiments, the distal tip of the docking device canfurther be modified, for example, with more material removed to formlarger cuts, making the distal portion of the docking device even moreflexible, so that the tip can more easily be actuated and manipulated tomore effectively navigate it around and encircle differentcardiovascular anatomies. A pattern can be laser cut to reduce theforces more in one area than another. The tube can be ovalized, that isthe cross-section area of the tube can be ovalized, so that the forcesallow the tube to curve in a desired direction. The tensioning wire canalso be clamped at both a proximal and a distal end of the tube, toprovide a tensioning force. Exemplary cut patterns are illustrated, butother cut patterns are also possible.

Various mechanisms can further be incorporated or added to one or moreof the docking devices described herein (e.g., herein docking devices 1,100, 200, 300, 400, 500, 600, and 1100), for example, in order toincrease the retention force between the docking device and areplacement valve that is expanded therein. Generally, coil-shapeddocking devices will have two open or free ends after implantation. Whena THV or other replacement valve is expanded in the coil, the coil canpartially unwind and increase in diameter due to the outward pressureapplied by the expanding valve on the coil, which in turn reduces theretention force applied by the coil on the valve. Mechanisms or otherfeatures can therefore be incorporated into the docking devices toprevent or reduce unwinding of the coil when the replacement valve isexpanded in it, resulting in an increase in radial forces and retentionforces between the docking device and the valve. Such mechanisms can beincorporated in lieu of modifying the size and shape of the dockingdevice, for example, without making the coil thicker or reducing thediameter of the inner space formed by the coil, both of which cannegatively affect the performance or ease of delivery of the dockingdevice. For example, when the coil of the docking device itself is madethicker, the increased thickness results in a more rigid coil, making itmore difficult to pass the docking device through a delivery catheter.Meanwhile, when the diameter of the inner space formed by the coil isreduced too much, the reduced space can prevent the expandable valvefrom fully expanding.

A first alternative modification to ensure sufficient retention forcebetween a docking device and a valve that is expanded in the dockingdevice is shown in FIG. 14. The docking device 300 in FIG. 14 includes amain coil 310 (which can be similar in size and shape to one of thedocking devices described above) and anchors 320 extending from the twofree ends of the coil 310. The anchors 320 are sized, shaped, orotherwise configured to embed themselves into the surrounding tissue(e.g., into the atrial and/or ventricular walls), for example, when areplacement valve is expanded in the docking device 300. The anchors 320can be barbed to promote ingrowth once the anchors 320 are embedded intothe heart walls or other tissue. The anchors can be any of manydifferent shapes and sizes. The anchors can extend from the end or fromany area near the end. Optionally, anchors or barbs can also bepositioned at various locations along the length and outer surface ofthe docking device.

In operation, when the docking device 300 is deployed at the mitralanatomy, once the docking device 300 is positioned through the mitralvalve, one end of the docking device 300 is positioned in the leftatrium while the other end of the docking device 300 is positioned inthe left ventricle. The shape and size of the coil 310 of the dockingdevice 300 can be selected and optimized to ensure that the ends of thecoil 310 respectively abut against the atrial and ventricular walls whenthe docking device 300 is advanced to the desired position. The anchors320 at the ends of the coil 310 can therefore anchor themselves into therespective heart walls. When the replacement valve is expanded in thecoil 310, the free ends of the coil 310 are held in position by theanchors 320 being lodged in the heart walls. The inability of the freeends of the coil 310 to move when the replacement valve is expanded inthe docking device 300 prevents the coil 310 from unwinding, therebyincreasing the radial forces applied between the docking device 300 andthe expanded valve and improving the retention force between thecomponents.

FIG. 15 shows a schematic view of a portion of another modified dockingdevice for improving retention forces between the docking device and areplacement valve. Portions of three turns of a docking device 400 areillustrated in FIG. 15. The docking device 400 includes a main coil orcore 410, which can be for example, a NiTi coil/core, or a coil/corethat is made of or includes one or more of various other biocompatiblematerials. The docking device 400 further includes a covering 420 thatcovers the coil/core 410. The covering 420 can be made of or include ahigh friction material, so that when the expandable valve is expanded inthe docking device 400, an increased amount of friction is generatedbetween the valve and the covering 420 to hold a shape of the dockingdevice 400 and prevent or inhibit/resist the docking device 400 fromunwinding. The covering can also or alternatively increase the amount offriction between the docking device and native leaflets and/or theprosthetic valve to help retain the relative positions of the dockingdevice, leaflets, and/or prosthetic valve.

The covering 420 is made from one or more high friction materials thatis placed over the coil wire 410. In one embodiment, the covering 420 ismade of or includes a PET braid over an ePTFE tube, the latter of whichserves as a core for the covering 420. The ePTFE tube core is porous,providing a cushioned, padded-type layer for struts or other portions ofa frame of the expandable valve to dig into, improving engagementbetween the valve and the docking device 400. Meanwhile, the PET layerprovides additional friction against the native valve leaflets when theprosthetic valve is expanded and the struts or other portions of thevalve frame apply outward pressure on the docking device 400. Thesefeatures can work together to increase radial forces between the dockingdevice 400 and the native leaflets and/or prosthetic valve, thereby alsoincreasing retention forces and preventing the docking device 400 fromunwinding.

In other embodiments, the covering 420 can be made from one or moreother high friction materials that covers the coil 410 in a similarmanner. The material or materials selected for making the covering 420can also promote rapid tissue ingrowth. In addition, in someembodiments, an outer surface of a frame of the replacement valve canalso be covered in a cloth material or other high friction material tofurther increase the friction force between the docking device and thevalve, thereby further reducing or preventing the docking device fromunwinding. The friction provided by the covering can provide acoefficient of friction greater than 1. The covering can be made ofePTFE and can be a tube that covers the coil, and can be smooth or canhave pores (or be braided or have other structural features that providea larger accessible surface area like pores do) to encourage tissueingrowth. The covering can also have a PET braid over the ePTFE tubewhen the ePTFE tube is smooth. The outermost surface of the covering orbraid over the covering can be any biocompatible material that providesfriction, such as a biocompatible metal, silicone tubing, or PET. Poresize in the covering can range from 30 to 100 microns. In embodimentswhere there is a PET covering on top of the ePTFE, the PET layer is onlyattached to the ePTFE covering, and not directly to the coil of thedocking device. The ePTFE tube covering can be attached to the dockingdevice coil at the coverings proximal and distal ends. It can be laserwelded on to the coil, or radiopaque markers can be placed on theoutside of the ePTFE tube covering or PET braid and swaged to thematerials to hold them in place to the coil.

Meanwhile, in some embodiments, the docking device 400 can also includeanchors similar to anchors 320 discussed above to further increaseretention forces, but other embodiments of the docking device mayincorporate the covering 420 without further including any suchadditional end anchors. Once the replacement valve is expanded in thedocking device 400 and the resulting assembly begins functioning as acombined functional unit, any tissue ingrowth can also serve to reducethe load on the combined valve and dock assembly.

The covering 420 can be added to any of the docking devices describedherein (e.g., docking devices 1, 100, 200, 300, 400, 500, 600, and 1100)and can cover all or a portion of the docking device. For example, thecovering can be configured to only cover the functional coils, theleading coil, the stabilization coil, or just a portion of one or moreof these (e.g., just a portion of the functional coils)

FIGS. 16 and 16A schematically show a portion of yet another modifieddocking device that improves retention forces between the docking deviceand a replacement valve. As is illustrated in the sectional view of FIG.16A, the valve leaflet tissue 42 undulates to conform to the varyingcross-section between the areas of the coil 510 with frictional elements510 and without the frictional elements. This undulating of the leaflettissue 42 results in a more secure entrapment of the tissue 42 betweenthe docking device 1 and the valve frame 41. The docking device 500 inFIG. 16 includes a main coil 510 and one or more discrete frictionelements 520 that are spaced apart along a length of the coil 510. Thefriction elements 520 can be made from a cloth material or other highfriction material, such as PET, and can be formed as small bulges on thesurface of the coil 510 or on another layer that is placed on the coil510. In some embodiments, the covering 420 can itself be considered africtional element or be configured to form one or more of thefrictional elements 520. In some embodiments, the friction elements 520are added on top of adding a high friction covering 530 that is similarto the covering 420 discussed above. An example of a docking device 500with both a high friction covering 530 and friction elements 520 appliedover a main coil 510 is schematically illustrated in FIG. 17.

When an expandable valve is expanded in the docking device 500, frictionis formed between the frame of the valve and the friction elements 520and/or between the frame of the valve, the native valve leaflets, andthe docking device that prevents or inhibits/resists the coil 510 of thedocking device 500 from unwinding. For example, the friction elements520 can engage or otherwise extend into cells defined by the frame ofthe expandable valve and/or force valve leaflet tissue into cells of theexpandable valve. In addition, when the valve is expanded in the dockingdevice 500, each of the friction elements 520 can engage with adjacentturns of the docking device 500 above and/or below the friction element520, and/or with one or more other friction elements 520 on the adjacentturns of the docking device 500. Any or all of these such engagementswill cause the docking device 500 to inhibit or resist unwinding,thereby increasing the retention force between the docking device 500and the expanded valve.

FIG. 18 schematically shows parts of three turns of still anothermodified docking device 600 that helps improve retention forces betweenthe docking device and a replacement valve. The docking device 600includes a coil 610 that is modified with one or more interlocking lockand key patterns spaced apart along the length of the coil 610. The lockand key patterns can be simple, for example, a rectangular groove orcutout 618 and a complementary rectangular projection 622, as generallyillustrated in FIG. 18, or can be made of or include different shapesand/or more complex patterns in other embodiments. In addition, thegrooves 618 and projections 622 can all be arranged in a same axialdirection or in different axial directions in varying embodiments. Thelock and key patterns or other frictional elements can be placed on thefunctional turns of the docking device.

When an expandable valve is expanded in the docking device 600, the lockand key mechanism relies on adjacent turns of the coil 610 abuttingagainst one another and on each turn interlocking with adjacent turns ofthe coil 610 located above and/or below it when one or more of theprojections 622 engage corresponding grooves 618. The interlocking ofthe grooves 618 and the projections 622 prevents relative motion betweenthe respective features, consequently also preventing the coil 610 ofthe docking device 600 from physically unwinding. Therefore, thisarrangement also serves to increase the radial forces and the finalretention force between the docking device 600 and a replacement valvethat is expanded in the docking device 600.

FIG. 19 shows a perspective view of an exemplary coil anchor or dockingdevice. The docking device 1100 in FIG. 19 can be the same as or similarin structure to the docking device 100 in FIG. 10 described above andcan include any of the features and characteristics described withrespect to docking device 100. Docking device 1100 can also include acentral region 1110, a lower region 1120, an upper region 1130, and anextension region 1140. The lower and upper regions 1120, 1130 can formlarger coil diameters than the central region 1110, and the extensionregion 1140 can space the upper region 1130 apart from the centralregion 1110 in a vertical direction, also similarly as previouslydescribed. The docking device 1100 is also arranged or wound so thatadvancement of the docking device 1100 into the left ventricle can beperformed in a counter-clockwise manner viewing the annulus in theoutflow direction (e.g., from atrium to ventricle). Other embodimentsmay instead facilitate clockwise advancement and placement of thedocking device.

In the embodiment in FIG. 19, the central coils/turns 1110 of thedocking device 1100 also serve as the functional coils/turns, andprovide a main docking site for a prosthetic valve or THV that isexpanded therein. The central turns 1110 will generally be positioned inthe left ventricle, while a small distal portion, if any, will extendthrough the native valve annulus and into the left atrium, described ingreater detail below. In examples where a THV has a 29 mm expanded outerdiameter, the central turns 1110 can have an inner diameter ranging from20 mm to 30 mm, and in an exemplary embodiment can be approximately 23mm (e.g., ±2 mm), in order to provide about 16 N of retention forcebetween the parts, which is sufficient for stabley holding the expandedTHV in the docking device 1100, and preventing the THV from dislodgingfrom the docking device 1100, even during severe mitral pressures.

Meanwhile, the lower region 1120 of the docking device 1100 serves as aleading coil/turn (e.g., a ventricular encircling turn). The lowerregion 1120 includes the distal tip of the docking device 1100, andflares radially outwardly from the central turns 1100, in order tocapture the native valve leaflets, and some or all of the chordae and/orother mitral anatomy, when the docking device 1100 is advanced into theleft atrium. Native mitral valves exhibiting mitral regurgitationtypically measure about a 35 mm A2P2 distance and a 45 mm distance fromcommissure to commissure. Therefore, when a THV that is 29 mm is used,the small size of the THV, and consequently the size of the centralturns 1110, are smaller than the long axis of the mitral anatomy. Assuch, the lower region 1120 is formed to have an enlarged size orprofile compared to the central turns 1110, in order to initially guidethe docking device 1100 more easily around both of the native valveleaflets. In one example, the diameter of the lower region 1120 can beconstructed to be about the same as the distance measured between thecommissures of the native valve (e.g., 45 mm), such that the distal tipwill extend approximately that distance away from the outlet of thedelivery catheter during delivery of the docking device 1100.

The upper region 1130 of the docking device 1100 serves as thestabilization coil/turn (e.g., atrial coil/turn) that provides thedocking device 1100 with a self-retention mechanism during thetransition phase after the docking device 1100 is deployed at the nativevalve and prior to delivery of the THV. The left atrium generally flaresoutwardly from the mitral annulus, forming a funnel-like shape thatwidens away from the annulus. The diameter of the upper region 1130 isselected to allow the upper region 1130 to fit at an approximate desiredheight in the left atrium, and to prevent the upper region 1130 fromsliding or dropping further towards the native mitral annulus after thedesired position is achieved. In one example, the upper region 1130 isformed to have a diameter from 40-60 mm, such as a diameter of about 53mm.

In addition, the shape and positioning of the upper region 1130 areselected such that after the THV is expanded in the docking device 1100,the upper region 1130 applies minimal or no pressure to the portion ofthe atrial wall that is adjacent to the aortic wall. FIG. 20 is aschematic top view of a portion of a heart, showing an approximation ofthe left atrium 1800, and the mitral valve 1810 positioned at a centralregion thereof. In addition, an approximate position of the aorta 1840is also schematically illustrated. Meanwhile, a docking device 1100 hasbeen delivered to the native mitral valve 1810 at commissure A3P3 1820.Of note here, the upper region 1130 of the docking device 1100 ispositioned away from a wall 1830 of the left atrium 1800 that isadjacent to the aorta 1840. Furthermore, when the THV is expanded in thedocking device, the central region 1110 of the docking device 1100 willtend to slightly expand and unwind, which can further draw the upperregion 1130 away from the atrial wall 1830 (e.g., counter-clockwise anddownward as illustrated in FIG. 20). Additional details of thepositioning of the docking device 1100 relative to the mitral valve1810, with further reference to FIG. 20, will be discussed in greaterdetail below.

The extension region 1140 provides a vertical extension and spacingbetween the central region 1110 and the upper region 1130 of the dockingdevice 1100. In some embodiments, the extension region 1140 of thedocking device 1100 (and extension 140 of docking device 100) cantherefore be referred to as an ascending turn. The location at which thedocking device 1100 crosses the mitral plane is important in preservingthe integrity of the native valve anatomy, and specifically the valveleaflets and commissures, to serve as an appropriate docking site forthe final implantation of the THV. In docking devices without such anextension or ascending region 1140, more of the docking device would siton or against the mitral plane and pinch against the native leaflets,and the relative motion or rubbing of the docking device against thenative leaflets could potentially damage the native leaflets from theatrial side. Having an extension region 1140 allows the portion of thedocking device 1100 that is positioned in the left atrium to ascend awayand be spaced apart from the mitral plane.

In addition, the extension region 1140 of the docking device 1100 canalso have a smaller diameter cross-section. In the embodiment shown, thewire core of other regions of the docking device 1100 can have adiameter of, for example, 0.825 mm, while the core of the extensionregion 1140 can have a diameter of 0.6 mm. In another embodiment, thewire core of other regions of the docking device has a cross sectiondiameter of 0.85 mm, and the extension region has a cross-sectiondiameter of 0.6 mm. When the other regions of the docking device coilhave a cross-section diameter of 0.825 mm or greater, or a cross-sectiondiameter of 0.85 mm or greater, the extension region 1140 can have across-section diameter of 0.4 to 0.8 mm. The thicknesses can also bechosen based on a ratio to one another. The extension region can have across-section diameter that is 50% to 75% of the cross-section diameterof the rest of the portions of the wire. An extension region 1140 with asmaller cross-section can allow for a sharper angle of ascension of theextension region 1140 from the mitral plane. The radius of curvature andthe wire cross-section of the extension region 1140 can further beselected, for example, to provide a sufficient connection point betweenthe central region 1110 and the upper region 1130 of the docking device1100, and/or to allow the extension region 1140 to be deployed andretrieved more easily with smaller forces during delivery, since athinner wire core is generally easier to straighten and bend. Inaddition, in embodiments where a shape memory such as NiTi is used forthe wire core, the thicknesses of both the extension region 1140 and therest of the docking device 1100 should be chosen so as not to exceed anystrain limits, based on the material properties of the material ormaterials selected.

While as noted above, a wire core of the docking device 1100 can be madeof NiTi, another shape memory material, or another biocompatible metalor other material, the wire core can be covered by one or moreadditional materials. These cover or layer materials can be attached ina variety of ways including, for example, adhesion, melting, molding,etc. around the core or otherwise suturing, tying, or binding thecover/layer to the wire core. Referring briefly to FIG. 22, across-section of a distal portion of the docking device 1100 includes awire core 1160 and a cover layer 1170. The wire core 1160, for example,can provide strength to the docking device 1100. Meanwhile, a basematerial of the cover layer 1170 which covers the wire core 1160 can be,for example, ePTFE or another polymer. The cover layer 1170 can be morecompressive than the wire core 1160, so that the wire frame and/orstruts of the THV can partially dig into or otherwise anchor into thecover layer 1170 for added stability when the THV is expanded in thedocking device 1100. A more compressible material will also allow thepinching or compression of the native valve leaflets and other anatomybetween the docking device 1100 and the THV to be less traumatic,leading to less wear and/or damage to the native anatomy. In the case ofePTFE, the material is also not water or blood permeable, but will allowethylene oxide gas to pass or penetrate through, thereby providing alayer through which the underlying wire core 1160 can be more easilysterilized. Meanwhile, while not blood permeable, an ePTFE cover layer1170 can be constructed with, for example, a 30 micron pore size, tofacilitate easy anchoring of blood cells in and against the outersurface of the cover layer 1170, for example, to promote in-growth oftissue after implantation. Furthermore, ePTFE is also a very lowfriction material. A docking device 1100 with an ePTFE cover layer 1170will provide for stability and promote in-growth.

While a low friction ePTFE cover layer 1170 can help with interactionsbetween the ends of the docking device 1100 and the native heartanatomy, additional friction may be more desirable in the central region1110, which provides the functional coils of the docking device 1100 fordocking the THV. Therefore, as seen in FIG. 19, an additional covering1180 (which can, optionally, be the same as or similar to covering 420and/or friction elements 520) can be added to the central region 1110 ofthe docking device 1100, on top of the ePTFE layer 1170. FIG. 19Aillustrates a cross-section view of the layers. The covering 1180(depicted as a braided layer) or other high friction layer providesadditional friction between adjacent coils and against the nativeleaflets and/or THV when the THV is expanded in the docking device 1100.The friction that is formed at the interfaces between coils and betweenthe inner surface of the central region 1110 of the docking device 1100,the native mitral leaflets, and/or the outer surface of the THV createsa more secure locking mechanism to more strongly anchor the THV and thedocking device 1100 to the native valve. Since the functionalcoils/turns or central region 1110 of the docking device 1100, that is,the region of the docking device that interacts with the THV, isgenerally the only region where a high friction covering/layer isdesired, as seen in FIG. 19, the braid layer or high frictioncovering/layer 1180 does not extend into either the lower region 1120 orthe extension region 1140, so that those regions of the docking device1100, along with the upper region 1130, remain low friction, in order tofacilitate less traumatic interactions with the native valve and otherheart anatomy. Additional friction elements and thus improvement inretention forces between the docking device and a replacement valve, canalso be added to the device through any combination of the high frictioncovering/layer 1180 and high friction elements or other featuresdescribed herein and illustrated in FIGS. 15-18.

FIG. 20 shows a top view of a possible placement of the docking device1100 at the native mitral valve 1810 prior to expansion of a THVtherein. In this embodiment, the docking device 1100 is advancedcounterclockwise through commissure A3P3 1820 of mitral valve 1810 andinto the left ventricle. When a desired amount of the docking device1100 (e.g., the lower region 1120 and much of the central region 1110)has been advanced into the left ventricle, the remaining turns of thedocking device 1100, for example, any remaining part of the centralregion 1110 (if any), the extension region 1140 (or a portion thereof),and the upper region 1130, is then released from the delivery catheter,for example, by a clockwise or opposite rotation of the deliverycatheter, such that these parts of the docking device 1100 can beunsheathed or otherwise released while a position of the central region1110 and the lower region 1120 of the docking device 1100 remainsstationary or substantially in position relative to the surroundinganatomy. In FIG. 20, portions of device 1100 below the native valve aredepicted with dotted lines.

A correct positioning of the docking device 1100 can be very important.In one embodiment, the docking device 1100 should be positioned relativeto the native valve 1810 such that a desired part of the docking device1100 extends through the native valve 1810 at or near commissure A3P3,and comes into contact with the atrial side of the native leaflets. Ascan be seen, for example, in FIG. 19, a proximal portion of the centralregion 1110 of the docking device 1100 extends between the proximal endof the covering or braid layer 1180 and the extension region 1140, wherethe ePTFE or low friction layer 1170 remains exposed. Preferably, thisePTFE or low friction region is the part of the docking device 1100 thatcrosses the mitral plane and comes into contact with the atrial side ofthe native leaflets. Meanwhile, the portion of the docking device 1100that passes through the mitral valve can be, for example, the part ofthe exposed central region 1110 just proximal to the end of the coveringor braid layer 1180, or can also include some of the proximal end of thecovering or braid layer 1180 as well.

Advancement of the lower coils or ventricular coils of the dockingdevice 1100 into the left ventricle should be precise. To facilitatethis one or multiple marker bands or other visualization features can beincluded on any of the docking devices described herein. FIG. 21 shows atop view of a modified embodiment of the docking device 1100, where twomarker bands 1182, 1184 have been added to the docking device 1100. Themarker bands 1182, 1184 are positioned next to one another. While themarker band(s) and/or visualization feature(s) can be placed at variouslocations, in FIG. 20, a first marker band 1182 is positioned at theproximal end of the high friction layer 1180, while a second marker band1184 is positioned a small distance away from the proximal end of thehigh friction layer 1180. One marker band 1182 can be made thicker thanthe other marker band 1184, in order to easily tell them apart. Themarker bands 1182, 1184 or other visualization feature(s) providelandmarks to easily identify the position of the proximal end of thehigh friction layer 1180 relative to both the delivery catheter and thenative mitral anatomy. Therefore, a physician can use the marker bands1182, 1184 or other visualization feature(s) to determine when to stopadvancing the docking device 1100 into the left ventricle (e.g., whenthe marker bands are at a desired orientation proximate commissureA3P3), and to start releasing or unsheathing the remaining proximalportion of the docking device 1100 into the left atrium. In oneembodiment, the marker bands 1182, 1184 are visualized under fluoroscopyor other 2D imaging modality, but the invention should not be limitedthereto. In some embodiments, one or both marker bands are insteadpositioned on the low friction layer 1170 proximal to the end of thebraid layer 1180, or on other portions of the docking device 1100, basedon user preference. In other embodiments less or more marker bands canbe used. The braid layer 1180 can extend across the portion of thedocking device coils that engages the replacement heart valve.

Any of the docking devices herein can be further modified, for example,to ease or assist in advancement of the docking device to an appropriateposition relative to the native valve. Modifications can also be made,for example, to help protect the native valve and other native hearttissue from being damaged by the docking device during implantation andpositioning of the docking device. For mitral applications, when aleading or distal tip of a coil-shaped docking device similarly aspreviously described is introduced into and rotated into position in theleft ventricle, the distal tip can be sized, shaped, and/or otherwiseconfigured to more easily navigate around and encircle the chordaetendineae. On the other hand, the distal tip should also be made in anatraumatic manner, such that advancement of the distal tip around and/orthrough the mitral or other valve anatomy will not damage the anatomy.

Meanwhile, in some embodiments, the proximal end of the docking deviceis attached to a pusher in the delivery catheter that pushes the dockingdevice out of a distal opening of the catheter. The terms pusher, pusherdevice, and push rod are used interchangeably herein and can besubstituted for each other. While attached to the docking device, thepusher can assist in both pushing and pulling or retrieval of thedocking device relative to the delivery catheter, in order to enablerepositioning of the docking device at any stage throughout the deliveryprocess. Methods described herein can include various steps related toretrieval and repositioning of the docking device, e.g., retracting orpulling a push rod/suture/tether or other feature to pull/retract thedocking device back into the delivery catheter, then repositioning andreimplanting the docking device in a different position/orientation orlocation. For docking devices that have a cover layer, such as a fabriclayer, that covers a coil skeleton of the docking device, adjustments ofthe docking device by the pusher can lead to friction forces appliedagainst the cover layer, particularly at portions located at theproximal and distal ends of the docking device, for example, by theheart anatomy and/or by the pusher/push rod/pusher device itself.Therefore, the structure at the ends of the coil of the docking deviceand the connection techniques (e.g., adhesion or suturing techniques)for connecting the fabric layer to the coil can both be important forhandling and dealing with such friction forces and to prevent tearing ofthe fabric layer from the coil or the ends of the coil.

In view of the above considerations, the docking device 1100 can includeatraumatic distal and proximal tips. FIG. 22 shows a cross-section ofthe proximal tip of the docking device 1100, showing the respectivegeometries of the wire core 1160, for example, that can be made of NiTi,and a low friction cover layer 1170, for example, that can be made ofePTFE or another polymer. The low friction cover layer 1170 can extendslightly farther past the end of the wire core 1160 and taper down to arounded tip. The rounded extension region provides space for the lowfriction cover layer 1170 to anchor to and around the wire core 1160,while also forming an atraumatic tip. The distal tip of the dockingdevice devices herein (e.g., docking device 1100) can be constructed orarranged to have a similar structure.

Referring to FIGS. 19 and 22, the docking device 1100 can optionallyfurther include securing holes 1164 near each of the proximal tip anddistal tip. The securing holes 1164 can be used to further secure thecover layer 1170 to the wire core 1160, for example, via a suture orother tie-down. This and/or similar securing measures can furtherprevent slipping or movement between the core 1160 and the cover layer1170 during deployment and/or retrieval of the docking device 1100.Optionally, the cover layer 1170 can be adhered, melted, molded, etc.around the core without suturing.

In some embodiments, the distal tip of the docking device 1100 can betapered slightly radially inwardly, for example, to be tangential to thecircular shape formed by the coils of the central region 1110.Similarly, the stabilization coil/turn or the upper region 1130 of thedocking device 1100 can also taper slightly radially inwardly, forexample, to be tangential (or have a portion that is tangential) to thecircular shape formed by the coils of the central region 1110, and canalso be, for example, pointed slightly upwards towards the atrialceiling and away from the other coils of the docking device 1100. Theupper region 1130 of the docking device 1100 can be configured in thismanner as a precautionary measure, for example, in case the dockingdevice 1100 is not placed in the desired position discussed above andslides towards the left ventricle, where the upper region 1130 couldpotentially come into contact with the mitral plane, or if the dockingdevice 1100 is being implanted into a heart with an abnormal anatomy.

With respect to facilitating attachment of the docking device 1100 to apusher/push rod or other advancement or retrieval mechanism in thedelivery catheter, the proximal end of the docking device 1100 canfurther include a second hole or bore 1162. As illustrated in FIG. 22A,the hole or bore 1162 can be sized such that a holding device, such as along release suture 1163, can be looped therethrough for connecting orattaching the docking device 1100 to the distal end of the pusher orother feature of the delivery catheter. The hole 1162 can be rounded andsmooth to prevent unintended severing of the release suture. The releasesuture provides a more secure attachment of the docking device 1100 tothe delivery catheter, and can also allow for a pulling retrieval of thedocking device 1100 when retraction of the position of the dockingdevice 1100, partial retrieval, or full retrieval is desired. FIG. 22Cillustrates a closer view of the release suture 163 looped through thebore 1162 of the docking device 1100, where the exterior of the deliverycatheter 1010 has been cut away. A pusher device 1165 is configured as apusher tube with a lumen extending therethrough, e.g., from end to end.The suture in this embodiment runs through a longitudinal bore throughthe pusher device/tube 1165 held within the delivery catheter 1010.Meanwhile, once a desired positioning of the docking device 1100 hasbeen achieved, the physician or other user can simply cut a proximalportion of the release suture and pull the release suture proximally topass the cut end of the suture out through the hole 1162, therebyreleasing the docking device 1100 from the delivery catheter. In oneembodiment, the suture can be looped and extended such that the sutureextends from the bore 1162 through the pusher device/tube 1165 to ahandle or hub external to the patient (the loop can be closed or openwith two ends secured to the handle or hub). When cut, a portion of thesuture can remain attached to the handle or hub (or be otherwise held bythe health care provider), which can allow the suture to be pulledproximally until the cut end comes out of the bore 1162 to release thedelivery device. FIG. 22B illustrates another embodiment of looping thesuture 1163 to the proximal end of the coil, through bore 1162.

Various further modifications can be made to either the distal tip orthe proximal tip of any of the docking devices described herein, or bothtips, which can make the docking device more robust. FIG. 23 shows adistal end of a coil skeleton or core of a docking device according toanother embodiment of the invention. The distal end of the coil/core 710can be made of or include Nitinol, another shape memory metal ormaterial, and/or non-shape memory materials. The distal end of thecoil/core 710 has a substantially flat or rectangular cross-section,with a distal ring-shaped tip 712. The rectangular cross-section showncan either be shaped in such manner only at a distal end of the coil710, or can extend for the length of the coil 710, while in otherembodiments, the entire coil 710, including the distal end region, canhave a more round cross-section or otherwise shaped cross-section. Thering-shaped tip 712 has an enlarged or expanded width compared to otherportions of the coil/core 710, and defines a through hole 714 tofacilitate passing through of one or more sutures. A free end 716 of thering-shaped tip 712 can be arranged as a circular or otherwise curvedarc, while an opposite proximal end 718 of the tip 712 can be formed asa rounded or tapered transition portion between the tip 712 and anadjacent region of the coil 710. Near the distal tip 712, the coil 710can further include one or more cover anchoring holes 720 to furtherassist in anchoring a cover layer that is placed over and attached tothe coil 710.

A cover layer that covers the coil skeleton/core 710 of the dockingdevice can be, for example, one or more of the coverings or layers(e.g., low friction and/or high friction covering(s)) previouslydescribed. The cover layer can be made of or include, for example, anePTFE core tube that is wrapped with a woven PET cloth, or can be madeof or include any other fabric or other biocompatible material. Such acover layer can be used to cover a majority of the docking device, forexample, from a main body of the coil skeleton/core 710 up to orslightly over the end 718 of the distal tip 712. The cover layer canthen be connected to the ring-shaped distal tip 712, for example, viasutures that are passed through the through hole 714 and that go on topof and cover the arched free end region 716. The sutures serve to anchorthe cover layer to the coil skeleton/core 710, and also serve to softenthe margins of the ring-shaped distal tip 712. Additional sutures canalso be passed through the one or more cover anchoring holes 720 nearthe distal tip 712, to provide additional anchoring of the cover layerto the coil skeleton/core 710.

FIG. 24 shows a distal end of a coil skeleton or core of a dockingdevice that can be used with any of the docking devices describedherein. The distal end of the coil/core 810 can also be made of orinclude Nitinol, another shape memory metal or material, and/or othernon-shape memory materials. The distal end of the coil/core 810 has adistal ball-shaped tip 812. The ball-shaped tip 812 can be preformedwith the rest of the coil skeleton/core 810, or can be a separateball-shaped or a short cudgel-shaped addition with a rounded end that iswelded to or otherwise attached to the distal end of the coil/core 810.Meanwhile, a small gap 814 is formed or left between the ball-shaped tip812 and the rest of the coil/core 810. The gap 814 can be approximately0.6 mm or any other size that is sufficient to facilitate passingthrough and/or crossing over of one or more sutures for anchoring orotherwise connecting a cover layer to the distal end of the coil/core810.

One or more cover layer(s) or covering(s) that covers the coilskeleton/core 810 of the docking device can be similar to previouslydescribed cover layers or coverings. The cover layer(s)/covering(s) canbe made of or include, for example, an ePTFE core tube that is wrappedwith a woven PET cloth, or can be made of or include any other fabric orother biocompatible material. In one attachment method, such a coverlayer/covering covers a main body of the coil skeleton 810, over the gap814, and up to or slightly over the ball-shaped tip 812, while leaving afree end of the ball-shaped tip 812 exposed. The cover layer/covering isthen connected to the distal end of the coil 810, for example, viasutures that are passed through the gap 814. In a second attachmentmethod, the entire ball-shaped tip 812 is wrapped with and fully coveredby the cover layer, and sutures are then passed through and/or crossedover the gap 814 to anchor the entire cover layer over the end of theball-shaped tip 812.

The distal tips 712, 812 as shown and described with respect to FIGS. 23and 24 provide their respective docking devices with distal ends thatare rounded with compact noses that enable easier and more convenientnavigation of their respective docking devices within the leftventricle. In addition, since each of the tips 712, 812 is curved orrounded, the tips 712, 812 form ends with soft edges. The shapes andstructures at the distal ends of the respective coil skeletons 710, 810,the type, texture, and construction of the cover layer, and the suturingtechniques for attaching the cover layer to the coil skeletons 710, 810also allow for tight connections between the distal tips 712, 812 andthe respective cover layers, without the use of glue or any otheradhesives. Furthermore, the tip construction and arrangements preventexposure of any sharp edges, and also prevent surfaces of the coilskeletons 710, 810 from cutting and/or protruding out of the coverlayers, as a result of any friction forces that are applied to the coverlayers of the docking devices during or after delivery.

As discussed above, in some embodiments, the docking device can beattachable to a pusher that can more easily facilitate pushing andpulling of the docking device for delivery and readjusting purposes.FIG. 25 shows a proximal end of a coil skeleton/core 910 of a dockingdevice 900 (which can be the same as or similar to other docking devicesdescribed herein), and FIG. 26 shows the proximal end of the dockingdevice 900, with a cover layer 920 over the coil skeleton/core 910, andsutures 930 attaching the cover layer 920 to the coil skeleton/core 910.

Referring first to FIG. 25, the coil skeleton/core 910 of the dockingdevice 900 has a proximal end region that has a substantially flat orrectangular cross-section, similar to the cross-section of the distalend of the coil/core 710 discussed above. The rectangular cross-sectionshown can either be shaped in such manner only at the proximal endregion of the coil/core 910, or can extend for the length of thecoil/core 910, while in other embodiments, the entire coil/core 910,including the proximal end region, can have a more round cross-sectionor otherwise shaped cross-section. An oval or elongate slit hole 912extends through the proximal end region of the coil/core 910, where twoflanks 914, 916 of the coil/core 910 extend along either side of theslit hole 912 to connect the proximal free end 918 of the coil/core 910to the rest of the coil/core 910. The slit hole 912 has a width that issufficient for passing through or crossing of a needle and/or one ormore sutures 930.

As shown in FIG. 26, the covering/cover layer 920 can be, for example, acovering, fabric layer, or other layer the same as or similarlyconstructed as discussed above with respect to previous embodiments ofthe docking device. The covering/cover layer 920 is wrapped around thecoil skeleton/core 910, and is anchored to or otherwise secured to thecoil/core 910 by sutures 930 that run along and are passed through theslit hole 912. The sutures 930 can be crossed through the slit hole 912in an “8” shape, as shown in FIG. 26, where a suture 930 is passedthrough the slit hole 912 at least twice and is wrapped around theopposite flanks 914, 916 of the coil/core 910 adjacent to the slit hole912 at least one time each. In the embodiment shown, the suture 930 ispassed through the slit hole 912 at least four times, and is wrappedaround the flanks 914, 916 at either side of the slit hole 912 at leasttwo times each. The sutures 930 are positioned at or moved towards aproximal portion of the slit hole 912, near the free end 918 of the coilskeleton/core 910, so that a distal end of the slit hole 912 remainsexposed and accessible to a user, and stays open and large enough, forexample, for a pull wire 940 (e.g., a release suture) of a pusher of thedelivery catheter to pass or cross through, thereby establishing asecure connection between the docking device 900 and the pusher. Thepull wire 940 can be a suture.

When the docking device 900 is connected to the pusher via the pull wire940, either a distal end of the pusher (not shown) abuts against theproximal free end of the docking device 900 or the pull wire 940 abutsagainst the distal end of the slit hole 912, in order to advance thedocking device 900 out of the delivery catheter. Meanwhile, when it isdesired for the docking device 900 to be pulled back or retracted, forexample, for readjusting a position of the docking device 900 at theimplant site, the pull wire 940 can be pulled proximally to retract thedocking device 900 proximally as well. Similar steps can be used withother docking devices herein. When the pull wire 940 is pulled back, thepull wire abuts against the sutures 930 that extend through the slithole 912, which by virtue of the “8” shape suturing, forms a crosssuture region that serve to provide a cushioned landing region againstwhich the pull wire 940 can abut. Therefore, the sutures 930 serve toanchor and attach the cover layer 920 to the coil skeleton/core 910,while also masking or covering the sharp edges of the slit hole 912, toprotect the pull wire 940 from being damaged or ruptured by the dockingdevice 900, and conversely to protect the docking device 900 from beingdamaged by the pull wire 940, during retrieval or other pulling of thedocking device 900.

Like the distal end arrangements discussed with respect to FIGS. 23 and24, the shape and structure at the proximal end of the coilskeleton/core 910, the type, texture, and construction of thecovering/cover layer 920, and the connection technique (e.g., suturingtechnique) for attaching the covering/cover layer 920 to the coilskeleton/core 910, each contributes to a tight connection between theproximal end of the coil 910 and the covering/cover layer 920, and canbe done without the use of glue or any other adhesives (e.g., thesuturing technique does not require these). Furthermore, the tipconstruction and arrangement prevents exposure of any sharp edges, andalso prevents surfaces of the coil skeleton/core 910 from cutting and/orprotruding out of the covering/cover layer 920, as a result of anyfriction forces that are applied to the covering/cover layer 920 of thedocking device 900 during or after delivery.

In various other embodiments, any or all of the different features fromthe different embodiments discussed above can be combined or modified,based on the needs of each individual patient. For example, thedifferent features associated with the various different issues (e.g.,flexibility, increasing friction, protection) can be incorporated intodocking devices as needed for each individual application, based on aparticular patient's specific characteristics or requirements.

Embodiments of docking devices herein have generally been discussedabove with respect to helping anchor replacement valves at the mitralposition. However, as has also been mentioned above, the dockingdevices, as described or slightly modified versions thereof, can also beapplied in similar manners to valve replacements at other valve sites aswell, for example, at the tricuspid, pulmonary, or aortic positions.Patients that are diagnosed with insufficiencies at either position canexhibit enlarged annuli that both prevent the native leaflets fromproperly coapting, and that also can cause the annuli to become toolarge, too soft, or too otherwise diseased to securely hold anexpandable valve therein. Therefore, use of a rigid or semi-rigiddocking device can also be beneficial for anchoring a replacement valveat those valve sites as well, for example, to prevent the replacementvalves from dislodging during normal heart function.

The docking devices herein can further be covered with one or morecoverings or cover layers, similarly as discussed above. In addition,cover layer(s) for any of these applications can also be made of orinclude a material that promotes more rapid tissue ingrowth. The coverlayer can further be constructed to have a larger amount of surfacearea, for example, with a velour film, porous surface, braided surface,etc., to further bolster tissue ingrowth.

Docking devices similar to those discussed above, when applied to valvesother than the mitral valve, can also provide a more secure landing zoneat those sites as well. The docking devices and associated replacementvalves can be applied similarly as has been discussed with respect toimplantation at the mitral valve. A possible access point for tricuspidreplacement can be, for example, transseptal access, while a possibleaccess point for aortic replacement can be, for example, transfemoralaccess, although access to the respective valve sites is not limitedthereto. The use of coil-shaped docking devices as previously describedat the other valve sites can also serve to circumferentially cinch orclamp the native leaflets after deployment of the replacement valve atthe native annulus, for example, by virtue of the leaflets and othertissue being sandwiched between coils of the docking device and beingheld in place by a spring force of the docking device, which furtherprevents slipping or other movement of the docking device and of thesandwiched tissue relative to the docking device, and prevents unwantedgrowth or expansion of the native annulus over time.

For purposes of this description, certain aspects, advantages, and novelfeatures of the embodiments of this disclosure are described herein. Thedisclosed methods, apparatus, and systems should not be construed asbeing limiting in any way. Instead, the present disclosure is directedtoward all novel and nonobvious features and aspects of the variousdisclosed embodiments, alone and in various combinations andsub-combinations with one another. The methods, apparatus, and systemsare not limited to any specific aspect or feature or combination thereofand can be combined, nor do the disclosed embodiments require that anyone or more specific advantages be present or problems be solved.

Although the operations of some of the disclosed embodiments aredescribed in a particular, sequential order for convenient presentation,it should be understood that this manner of description encompassesrearrangement, unless a particular ordering is required by specificlanguage set forth below. For example, operations or steps describedsequentially can in some cases be rearranged or performed concurrently.Moreover, for the sake of simplicity, the attached figures may not showthe various ways in which the disclosed methods can be used inconjunction with other methods. Additionally, the description sometimesuses terms like “provide” or “achieve” to describe the disclosedmethods. These terms are high-level abstractions of the actualoperations that are performed. The actual operations that correspond tothese terms can vary depending on the particular implementation and arereadily discernible by one of ordinary skill in the art.

In view of the many possible embodiments to which the principles of thedisclosure can be applied, it should be recognized that the illustratedembodiments are only preferred examples and should not be taken aslimiting the scope of the disclosure. Rather the scope of the disclosureis defined by the following claims.

What is claimed is:
 1. A docking device for docking a prosthetic valveat a native valve of a heart, the docking device comprising: a coiledanchor that comprises: at least one central turn defining a central turndiameter; a lower turn extending from the at least one central turndefining a diameter that is greater than the central turn diameter; anupper turn connected to the at least one central turn, the upper turnbeing shaped to have a first diameter along a first axis and a seconddiameter along a second axis, wherein the first axis diameter is greaterthan the central turn diameter, and wherein the second axis diameter isgreater than the central turn diameter and less than the lower turndiameter; and wherein the coiled anchor is configured to be implanted atthe native valve with at least a portion of the at least one centralturn of the coiled anchor positioned in a chamber of the heart andaround valve leaflets of the native valve.
 2. The device according toclaim 1, wherein the at least one central turn defines a diameterbetween 20 to 30 mm.
 3. The device of claim 1, wherein the lower turndefines a diameter between 30 to 75 mm.
 4. The device of claim 1,wherein the first axis diameter is between 40 to 80 mm, and the secondaxis diameter is between 20 to 80 mm.
 5. The device of claim 1, whereinthe first axis diameter is 40 to 75 mm, and the second axis diameter islarger than the diameter defined by the at least one central turn. 6.The device of claim 1, wherein the coiled anchor comprises a coiled wirehaving a rectangular cross-sectional shape with a thickness of at least0.8 mm.
 7. The device of claim 1, wherein the coiled anchor comprises acoil that has a circular or elliptical cross-sectional shape with athickness of at least 0.8 mm.
 8. The device of claim 1, wherein the atleast one central turn comprises between one half rotation turn to fivefull-rotation turns, the upper turn comprises between one half turn toone turn, and the lower turn comprises between one half turn to fiveturns.
 9. The device of claim 1, further comprising a suture removeablythreaded through a bore in the coiled anchor and configured to beconnected to a pusher device within a delivery catheter to provide ameans for retrieving the docking device.
 10. The device of claim 9,wherein the suture is removeably threaded through the bore at a locationalong a length of the suture and then the suture ends are threadedthrough a space between the central point of the suture and the proximalend of the coiled anchor.
 11. The device of claim 1, further comprisinga low friction cover layer, having a distal end and a proximal end,surrounding the coiled anchor and extending along a length of the coiledanchor, past a distal tip of the coiled anchor, and past a proximal tipof the coiled anchor, the low friction cover layer tapering to a roundedtip at its distal end and at its proximal end.
 12. The device of claim11, wherein the distal tip of the coiled anchor is tapered slightlyradially inward in a direction tangential to a circular shape formed bythe central turn.
 13. The device of claim 11, wherein the proximal tipof the coiled anchor is tapered slightly radially inwardly and ispointed in an upward direction.
 14. The device of claim 1, wherein thecoiled anchor further comprises an extension having a length extendingfrom an upper end of the central turn comprising a second thickness thatis less than a first thickness of the upper turn.
 15. The device ofclaim 14, wherein at least a portion of the extension extends verticallyat an angle of between 70-110 degrees relative to the at least onecentral turn.
 16. A system for implanting the docking device of claim 1at the native valve, comprising: a delivery catheter; a suture threadedthrough a bore in a proximal end of the device; and a pusher device,wherein the pusher device includes a central lumen; wherein the pusherdevice is disposable in the delivery catheter and the suture isdisposable in the central lumen such that pulling the suture and/or thepusher device proximally relative to the delivery catheter retracts thecoiled anchor into the delivery catheter.